SummaryNo recent population-based data on HIV testing in people with high-risk sexual behavior are available. We sought predictors of testing using data from the 1997 Los Angeles County Health Survey, a random-digit telephone survey of 8004 county households. An estimated 2.3 million (35.5%) adults were tested for HIV in the past 2 years and approximately 370,000 (5.6%) engaged in high-risk sexual behavior (defined as having ≥2 partners in the past 12 months and not always using condoms). Among high-risk persons, an estimated 46% of heterosexual men, 56% of heterosexual women, and 72% of men who had sex with men (MSM) were tested for HIV. In a multivariable model of high-risk people, both heterosexual men (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.16–0.61) and women (OR, 0.41; 95% CI, 0.19–0.87) had significantly lower proportions of testing than MSM. Although African Americans and Hispanics had significantly higher testing proportions than whites overall among all county residents, those reporting high-risk sexual behavior did not test at higher proportions. We conclude that the proportion of adults with high-risk sexual behavior tested for HIV is higher than almost a decade ago. However, testing among this group remains suboptimal. Future public health campaigns should intensify efforts to encourage HIV testing among this population.