To help those interested in using sexuality education to improve youth sexual and reproductive health (SRH) outcomes, the United Nations Educational Scientific and Cultural Organization (UNESCO), working with partners, developed the International Technical Guidance on Sexuality Education (ITGSE) in 2009. This two-volume global document offers guidance intended for governments, organizations, programs or individuals to adopt on a voluntary basis and adapt for individual contexts. The ITGSE provides decision-makers with 1) the rationale for offering comprehensive sexuality education, 2) the key characteristics of effective sexuality education, and 3) content suggestions for comprehensive sexuality education to help them design their own programs. It covers sexuality education in both primary and secondary school. Adaptation of the ITGSE can occur in a number of ways. Kenyan leaders in the Ministry of Education (MOE), seeking to capitalize on the wide reach of primary and secondary schooling in the country, worked with FHI 360 and UNESCO to use the ITGSE to strengthen sexuality education in their national curriculum. Their work was supported by the United States Agency for International Development’s (USAID) Interagency Youth Working Group (IYWG) and UNESCO. USAID-Kenya was also instrumental in the process. This document provides a step-by-step report of the process undertaken in Kenya and a description of the successes, challenges and lessons learned along the way. The adoption and adaptation of guidelines are more common practices in the health field. Thus, in this document, many of the lessons learned are compared with experiences in the education and health sectors, in the hope that this comparison provides additional useful information.