This publication describes three German-supported initiatives in Africa (specifically in Guinea, Mozambique and Tanzania) and one in Latin America (a six-country regional initiative). All integrate sexual health and HIV prevention within school systems. The three African initiatives operate within generalized epidemics driven largely by unprotected sex between men and women. In Latin America general prevalence in the countries described here is well below one percent, and much less among young people. Sex between men and, to a lesser extent, injecting drug use and sex work, play key roles in concentrated epidemics. Important sexual health issues in both regions include early sexual debut, low access to information and services (notably inexpensive condoms), and high levels of unplanned pregnancy. In Sub-Saharan Africa, birth rates among girls aged 15-19 in rural areas are almost double those in urban areas. Girls with a secondary education are the least likely to become mothers, while among uneducated girls the birth rate is over four times higher.