The finding of endocrine gland lesions at pathological examination in AIDS and reports of several cases of endocrine disease in patients with this syndrome have prompted us to study endocrine functions in 63 patients (51 men, 12 women) with HIV-1 infection. According to the Center for Disease Control (CDC) classification system, 13 of these patients were stage CDC II, 27 stage CDC III and 23 stage CDC IV. We explored the adrenocortical function (ACTH, immediate tetracosactrin test) and the thyroid function (free T3 and T4 levels, TRH on TSH test) in all 63 patients. The hypothalamic-pituitary-gonadal axis (testosterone levels, LHRH test) and prolactin secretion (THR test) were explored in the 51 men. The results obtained showed early peripheral testicular insufficiency at stage CDC II and early pituitary gland abnormalities with hypersecretion of ACTH and prolactin also at stage CDC II. On the other hand, adrenocortical and pituitary abnormalities were not frequently found. The physiopathology of the endocrine abnormalities observed in HIV-1-infected patients remains unclear, but one may suspect that it involves interleukin-1 since this protein factor has recently been shown to stimulate the corticotropin-releasing hormone secretion and to act directly on the glycoprotein capsule of the virus (gp 120) whose structure is similar to that of some neurohormones.