H.I.V. Education and Prevention Act of 2008 - Amends title V (Maternal and Child Health Services) of the Social Security Act to expand provisions for abstinence education to allow states to provide other sex education. Defines the term "sex education" to mean education about the functional, structural, or behavioral aspects of human reproduction and education about abstinence or contraception.
Directs the Secretary of Health and Human Services to establish a pilot program to make grants to public and nonprofit entities to provide: (1) substance abuse treatment services in the form of long-term counseling; (2) substance abuse prevention services to individuals who are less than 21 years of age; and (3) services that facilitate interaction between individuals receiving treatment for substance abuse and individuals receiving prevention services in a manner that enhances both such services.