We examined the psychological impact of HIV antibody testing in 107 homosexual men in San Francisco. Seventy-eight percent of the seropositives but only 43% of the seronegatives correctly anticipated their results. Twelve months after notification (but not earlier), notified seropositives reported significantly greater increases in total distress than nonnotified controls. However, notified seronegatives demonstrated significantly lower levels of hopelessness than nonnotified controls at every follow-up assessment. Thus, knowledge of HIV antibody status appears to dispel a sense of gloom in persons who incorrectly believe themselves to be infected with HIV, but does not appear to induce significant distress in those whose expectation of a positive result is confirmed. Both groups reported lower distress than men with ARC or AIDS, suggesting that distress was related more to symptomatology than knowing antibody status. These results suggest the benefits of HIV testing for the considerable proportion of seronegative subjects believing themselves to be seropositive and should be weighted against the more limited induction of distress in seropositives who receive confirmation of their test result expectation. The benefits of testing are also supported by increasing knowledge of the usefulness of early intervention in HIV disease.