SummaryWe compared endocrine function in patients with the HIV wasting syndrome with other HIV-positive patients without wasting to determine associations between endocrine dysfunction and wasting. Sixty-six HIV-seropositive patients were evaluated by thyroid, gonadal, and adrenal function tests. Fourteen of these patients met the clinical definition of wasting. Total and free testosterone levels were significantly lower in patients with wasting compared with patients without wasting with both similar and higher mean CD4 counts. Prolactin levels were significantly higher, and cortisol levels were higher with borderline significance in patients with wasting compared with patients with similar CD4 counts without wasting. These findings suggest that endocrine function in the HIV wasting syndrome differs from that of HIV-infected patients without wasting, which may have implications about the pathogenesis and treatment of the HIV wasting syndrome.