One-hundred and eighty-eight HIV-seropositive (index cases) and 45 HIV-seronegative (controls) homosexual men completed a questionnaire to assess their nutritional beliefs and practices, their psychosocial characteristics and information sources. Most individuals, irrespective of their HIV serological status, perceived the need to change their diet. Dietary changes were those which would be perceived as healthy by the general population, for example, a low-fat, high-fibre diet. Most HIV-seropositive individuals believed that vitamin and mineral supplements were especially important for their health and this was mirrored in their relative increased use of these substances compared to controls. Dietetic advice was not effective in terms of reported changes in dietary practice. This work shows that although dietetic advice could be important in the management of HIV infection, in terms of altering dietary intake to promote weight gain, current practice needs to be reviewed in an attempt to improve efficacy. These results highlight the need to consider psychological characteristics when monitoring dietary compliance.