The hazards of ultraviolet radiation (UVR) include immunosuppression, activation of human immunodeficiency virus (HIV) type 1 expression, and photocarcinogenesis particularly in immunosuppressed individuals. Fifty-eight male homosexuals positive for HIV antibody and 61 controls not at risk for HIV infection answered a questionnaire on their attitudes and exposure to natural and artificial sources of UVR. Controls were matched for sex but were not from an at-risk group for HIV infection. Mean ages were similar for both groups. HIV seropositives had greater recreational UVR exposure than controls: 12/58 versus 4/61 had regular use of a sunbed (P less than 0.05), and experienced 11.6 weeks versus 9.5 weeks of prolonged natural UVR exposure (P = 0.056) over a four-year period. One reason for this difference may be the misconception present in two-thirds of the HIV seropositive group that a suntan would improve their health and the outcome of their HIV infection. Those with HIV infection must be made aware that there is a potential for further immunosuppression and viral activation from UVR and they should be advised to avoid undue recreational exposure.