A 3-year-old boy with infection by the human immunodeficiency virus (HIV) developed stage IV Burkitt's lymphoma. Complete remission was achieved with the BFM-86 protocol. One month after finishing treatment, and still in complete remission, fever appeared and seropositivity to HIV was found. The child was diagnosed of AIDS (P2-E1) and died 10 days later. Although the association of HIV infection and Burkitt's lymphoma is well known in adults, it is extremely rare in children. The routine HIV screening is suggested for children with non-Hodgkin's lymphoma.