With the aim of comparing the clinical features of Burkitt's like lymphoma (BL) in HIV-infected patients and in the general population, we retrospectively analyzed 35 patients with HIV-positive non-Hodgkin's lymphoma (NHL) and 535 patients with HIV-negative NHL, from 1985 to 1990. A total of 33 patients with BL were diagnosed at our institute: 18 without and 15 with HIV infection; 3.3% and 43% of all HIV-seronegative and HIV-seropositive NHL respectively. No significant differences were found between these two series concerning clinical features, with the exception of peripheral adenopathy that was more common in the HIV infected patients (p = 0.05). In both groups BL was characterized by advanced stage and high incidence of bone marrow and gastrointestinal involvement. Response rate was lower in the HIV-positive patients, but the difference was not significant. No relevant differences in the toxicity after chemotherapy were observed. The median survival in the HIV-infected patients was lower (7 months) than in the other group (14 months), with borderline statistical significance (p = 0.06).