No Means No Worldwide (NMNW) is a global rape prevention organization whose mission is to end sexual violence against women and children. We train instructors in high-risk environments to deliver our proven IMpower rape prevention curricula to boys and girls ages 10-20. Wherever we teach, the incidence of rape drops by 50%. Girls learn to identify risk, say “no” and talk their way out of trouble. If that “no” is not respected, they also learn physical skills to back it up. Boys learn to challenge rape myths, ask for consent and intervene if they anticipate or witness predatory behavior. 

The Need

Globally, an estimated 35% of women experience some form of sexual violence in their lifetime. In Africa, that percentage increases to 45%. According to the UN Population Fund, almost 50% of all sexual assault victims are girls age 15 or younger. In the slums of Nairobi, where our programming started, 1 in 4 girls are raped every year. To a global community in need of a truly effective solution to gender based violence, NMNW is uniquely qualified to lead the effort.

Service Delivery

NMNW’s technical work includes training and certifying local male and female instructors to deliver the IMpower curricula and supporting them to monitor and evaluate our intervention and its implementation. We hold implementing partners to high performance standards, to ensure curricula fidelity and program efficacy.

Impact Highlights

NMNW has rigorously evaluated its program: our research partners have published four quasi-experimental studies and one randomized control trial (RCT) in peer-reviewed journals, with one RCT currently under analysis and another under review. Key findings include:

  • 50% decrease in the incidence of rape among female participants
  • 50% of female participants used program skills to stop a rapist in the year following the training, and 20% used the skills more than once
  • 74% of boys who witnessed physical or sexually assaultive behavior in the year following the program successfully intervened to stop it
  • 46% decrease in school dropouts due to teen pregnancy among schools where we teach

Impact Footprint

  • Programs through Ujamaa Africa in urban Kenya (since 2009) & rural Malawi   (since 2015)
  • More than 180,000 girls and boys aged 10-20 taught IMpower skills
  • At least 300,000 sexual assaults prevented
  • $7.44 to prevent a rape


It all started...

In 2006, No Means No Worldwide Founder Lee Paiva was walking through the Korogocho slum in Nairobi, Kenya to check on a microloan business. Her translator began whispering about the people and shacks they passed.

“This girl was raped at knife point, this child is a rape baby, this girl is HIV-positive from rape by her father, this is where a grandmother died after being gang-raped, this woman’s baby was raped...”

Lee felt she had entered a nightmare. A baby raped? A grandmother? It sounded as if every female there had been sexually assaulted. The translator shrugged as if to say, “It is what it is.”

This experience struck a personal chord in Lee, and she immediately set out to prove that “it” was a rights atrocity and the result of egregious gender-related power imbalances. She further sought to show that an education curriculum rooted in individual rights and  empowerment self-defense skills, similar to the one she had practiced in the United States, could be transferred to slum environments.

In October 2009, Lee started building No Means No Worldwide by designing and piloting a violence prevention and intervention system called IMpower. She worked closely with educational and academic experts across the globe to design curricula and training materials. The aim was to stop the cycle of violence by educating girls and boys to create gender equity for community-wide, generational change.

In 2011, Lee began training instructors to deliver IMpower programming. In 2012, she teamed up with the Kenyan nonprofit Ujamaa to  launch classes and gather data for impact evaluation. This effort led to the formation of the Gender-Based Violence Prevention Collaborative in partnership with Stanford University. The collaborative produced five scientific articles published in major international journals about the impact of NMNW’s work.

IMpower is now a leading dual-gender violence prevention curriculum for youth. The male and female IMpower Instructors trained since launching NMNW have taught over 180,000 girls and boys in Kenya and Malawi. In addition to pioneering cutting-edge prevention interventions, NMNW created a 12 Step recovery program for survivors called Sexual Assault Survivors Anonymous (SASA). These meetings are held across Nairobi and provide long-term steps to recovery free of charge.

In 2015, after three years of testing its program in Kenya, NMNW was ready to achieve transformative scale in preventing gender-based violence by becoming a best practice global training academy and technical assistance provider. NMNW’s technical assistance approach is to provide comprehensive support to existing local implementing partner organizations like Ujamaa, so the partners can deliver and evaluate high quality rape prevention programming.

To bring an end to the global rape epidemic, NMNW believes that education and training are central to prevention and that the decades-long focus on costly, reactive aftercare must end. NMNW has a measurable and proven model that has been verified as primary prevention to stop sexual harassment, assault and rape. Now, NMNW’s job is to spread that model as widely and as quickly as possible.


“What No Means No Worldwide is proving through its sexual assault intervention is that you don’t need to build 142 police stations, like they did in Tanzania, for millions of dollars. What you need to do is build training capacity in human beings and then train kids to use what’s already within themselves.”

—Catherine Maternowska,
Child protection specialist, Unicef Office of Research-Innocenti

LEE PAIVa Founder & CEO

Lee Paiva is founder and CEO of No Means No Worldwide and creator of IMpower, a dual-gender violence prevention and intervention program. Since 2007, she has implemented her program in the six largest slums of Nairobi, Kenya. In 2013, she partnered with researchers at Stanford University to form the GBV Prevention Collaborative, which led to her co-authorship of five peer-reviewed articles about the efficacy of IMpower classes in cutting rape and pregnancy-related school dropout by 50%. She also founded Sexual Assault Survivors Anonymous for survivors ages 5 and up. She is a Mulago Rainer Arnhold Fellow and her work has been featured on CNN, MSNBC, FOX, and ESPN, among others. She lives in San Francisco, California.



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Katherine Daiss – DEPUTY DIRECTOR, Development & Partnerships

Katherine Daiss is deputy director of No Means No Worldwide, overseeing development, partnerships and operations. She has driven the growth of NMNW’s global presence by building relationships with new donors and enabling partners. Prior to NMNW she worked in South Africa developing GBV and HIV prevention curriculum and training. Her business expertise stems from leadership consulting for Fortune 500 companies across North America, Europe and Asia.



Tamara Straus is deputy director of No Means No Worldwide, overseeing advocacy, communications, and development. She has over a decade of experience in nonprofit strategy and international development, having served as as senior editor at the Stanford Social Innovation Review, editorial director of UC Berkeley’s Blum Center for Developing Economies and a consultant for The Bridgespan Group and poverty-alleviation nonprofits working in North America, Africa and Asia. Tamara has written about female empowerment, sexual safety and other issues for Quartz, California Magazine, the San Francisco Chronicle and Mother Jones.



  • Carol Lloyd

Vice President, Editorial Director for GreatSchools, and award-winning journalist and author. Her writing appears in The New York Times Magazine, This American Life, Los Angeles Times,  San Francisco Chronicle and as well as being featured on NPR’s Talk of the Nation, and PRI’s The World.

  • Vida Sanford

San Francisco-based social worker and educator who has pioneered successful school-based mentoring programs and innovative research projects for the San Francisco Unified School District.

  • David Lisak

Clinical psychologist, researcher on rape and homicide, international forensic consultant, Founder, Bristlecone Project and Founding Board Member of 1in6.

  • Jennifer Keller

Ph.D., Clinical Associate Professor, Stanford University School of Medicine, Department of Psychiatry and Behavioral Sciences.

  • Maggie Law

Software Designer, team leader, and mentor who is excited to work for community-level efforts to improve the lives of women and children at massive scale.


  • Mary Catherine Maternowska

UNICEF Office of Research Innocenti


Founder and CEO Edgework Consulting


Founder Grassroots Soccer


UNICEF, Child Protection Specialist


Consultant,, MIT


Founder CEDOVIP, Uganda


Adolescent Health Advisor JHPIEGO, USA /  Kenya


Writer and Director of Beauty Bites Beast book, movie

  • Emily Scott

Philanthropic Director, The Resiliency Fund Guide/Facilitator, ES -The Power of And


In an effort to stay current with research in the field of sexual gender based violence (SGBV) prevention, NMNW offers six-month internships for volunteer researchers. Each month, the research group studies organizations working to prevent SGBV that have published peer-reviewed papers proving behavior change impact. This helps NMNW remain informed about advances in the SGBV field and incorporate aspects of what is working into programming and services. Our gratitude to the current research internship team: Grace Margaret Lovio, Yessenia Gomez, Erin Thomas, Natasha Richards and Rebecca Adamson. For information on joining this internship, contact