To determine the association between haematological malignancies and the HIV-1 in Yaounde, Cameroon, adult patients (>16 years) followed up in the Haematology Clinics of two major hospitals were screened for the HIV between 1994 and 1999. There were nine haematological malignancies diagnosed among the 172 patients including Non Hodgkin's lymphomas (31.9%); chronic lymphocytic leukaemia (21.5%); chronic myelogeneous leukaemia (18.0%); acute myelogeneous leukaemia (9.9%); acute lymphoblastic leukaemia (7.6%) and multiple myeloma (7.0%). Burkett's lymphoma, Hodgkin's disease and myelodysplastic syndrome had been less frequently diagnosed. Forty-five of all cases (26.2%) had antibodies to the HIV-1 virus, predominantly in patients with Non-Hodgkin's lymphomas (p