We examined changes and correlates of sexual risk behavior of men who have sex with men (MSM) compared with heterosexual men and women over three time periods. Data from the 1997, 1999, and 2003 Los Angeles County Health Surveys, a population-based telephone survey, were analyzed to examine the association of sociodemographic and health-related factors with sexual risk behaviors among the three groups. In each time period, MSM reported a significantly greater percentage of sexual risk (i.e., both inconsistent condom use and multiple sex partners in the past 12 months) compared with heterosexual men and women. Multivariate analyses indicated that MSM and heterosexual men reported greater sexual risk than heterosexual women. Respondents who were younger, U.S. born, reported heavy alcohol consumption, or had been tested for HIV in the past 24 months were more likely to report sexual risk behavior. The findings suggest the need for continued targeted prevention for MSM and prevention efforts for segments of the general population at elevated risk for HIV.