Summary A survey was carried out in a population of 503 HIV-infected patients attending a tertiary care centre of infectious diseases, to evaluate the spontaneously reported use of alternative therapeutic regimens for HIV disease. One-hundred and seventy-one out of the 412 evaluable patients (41.5%) used at least one unorthodox therapy within the previous 3 months. The recourse to non-conventional therapies increased significantly according to clinical and immunological progression of HIV disease, while no significant relationship was found when age, gender, risk for HIV infection, and duration of known HIV disease were assessed. Patients involved in alternative modes of treatments were more likely to refuse (or follow with poor compliance) antiretroviral therapy and/or anti- Pneumocystis carinii chemoprophylaxis. An elevated percentage of family physicians (46.2%) were unaware of alternative choices made by their patients. Finally, although 81.3% of individuals experiencing non-conventional treatments perceived satisfactory effects on their cenesthesis and health, a significant clinical and/or virological and/or immunological worsening of HIV disease occurred in more than 85% of patients failing to take properly antiretrovirals and/or P carinii prophylaxis.