This article describes the methods used and findings obtained in establishing the HIV/AIDS Prevention Program Archive (HAPPA), a collection of effective HIV/AIDS prevention programs in a box. The HAPPA collection builds on a previously established collection of 13 effective HIV/AIDS/sexually transmitted disease (STD) prevention programs for adolescents known as PASHA, the Program Archive on Sexuality, Health, & Adolescence. Together, the HAPPA and PASHA collections provide a rich source of 23 promising programs designed to prevent the spread of HIV/AIDS. The HAPPA and PASHA programs are available for use by communities, schools, family planning clinics, STD clinics, mental health centers, and drug rehabilitation centers throughout the country.