This paper reports data on the effects that Earvin ''Magic'' Johnson's announced HIV infection had on the clients of an Philadelphia sexually-transmitted-disease (STD) clinic. Interviews conducted after Johnson's announcement (N = 148) included questions about whether respondents had heard his announcement and how this news had influenced their sexual attitudes and behaviors. The findings include comparisons of matched samples (N = 138) of respondents interviewed before and after the news. The comparisons focused on 3 areas related to the human immunodeficiency virus (HIV): 1) passive concern; 2) sense of personal risk; and 3) resolve to be tested for HIV in the next 6 months. A significantly greater percent (92%) of the postannouncement respondents reported planning HIV tests than did the preannouncement respondents (52%). Although the differences in perceived risk were not statistically significant, 25% of the preannouncement and 34% of the postannouncement respondents indicated high perceived risk for HIV. Forty-four percent of the postannouncement sample indicated that, as a result of the news, they were now using condoms; 32% reported no effect; and 54% reported a variety of behavior changes that included monogamy (21%), greater selectivity (10.6%), fewer sexual partners (9.2%), and abstinence (3.5%). Overall, the announcement by Magic Johnson that he had been infected with HIV was associated with increased concern about HIV and with attitude and behavior changes that would lead to reduced risk. This was especially true for those in the sample at relatively higher risk.