Non-Hodgkin lymphoma (NHL) is rarely observed during infancy and data on its incidence, characteristics and outcome are scarce. The present study aimed to assess the prevalence, clinical presentation and treatment results of all infants who were diagnosed with NHL between October 1986 and December 2002 among 2084 patients treated according to the NHL-BFM (Berlin-Frankfurt-Münster) multicentre trials 86, 90 and 95. We identified 20 (1%) infants with NHL including five with T-cell lymphoblastic lymphoma (T-cell LBL), seven with precursor B-cell LBL (pB-cell LBL), two with a mature Burkitt neoplasm, five with anaplastic large cell lymphoma (ALCL) and one with peripheral T-cell lymphoma (PTCL). The PTCL patient, 3/7 pB-cell LBL and 1/5 ALCL patients relapsed. One patient each from the T-cell LBL and Burkitt lymphoma groups suffered from a second malignancy and one patient each with ALCL and Burkitt leukaemia died from treatment-related toxicity. The 5-year event-free survival rate was 53 +/- 12% for the 20 cases. This study has provided preliminary evidence that infants with NHL have a dismal prognosis and showed that infant NHL differed to lymphomas in older patients with respect to the distribution of gender, histopathologic subtypes as well as the ratio of T- to pB-cell LBL and the frequency of relapses of pB-cell LBL.