This paper explores the extent of change in acquired immunodeficiency syndrome (AIDS) risk level and in the numbers of AIDS-related risk behaviors in 602 inner-city adolescents as they enter young adulthood. Youths' risk level for human immunodeficiency virus (HIV) infection during adolescence was categorized as high (engaging in prostitution, male homosexual or bisexual activity, or injectable drug use or having ulcerative sexually transmitted diseases), moderate (having six or more sex partners in a 1-year period or nonulcerative sexually transmitted diseases), or low (none of the above). Although a proportion at high or moderate risk during adolescence did move to lower risk levels by young adulthood, the overall risk level stayed fairly stable: 45% were at high or moderate risk levels during adolescence, and 35% were at those levels by young adulthood. Then change in the total number of risk behaviors engaged in by the youths was examined. Knowledge about AIDS or HIV infection and its prevention was not associated with any change in risk behavior, nor were the number of sources of information about the epidemic, acquaintance with those who are infected, estimates of personal risk, or exposure to HIV-test counseling. In fact, youths whose risk behaviors increased the most were more likely to know someone who had died of AIDS and to estimate their own risk as high. Most youths reported that they did not use condoms regularly, disliked them, and had little confidence in their protective ability. Changes in preventive strategies and further research on the causes of behavior change are needed.