Among pediatric non-Hodgkin lymphomas, the most frequent type is small noncleaved-cell lymphoma (including Burkitt and Burkitt-like). Specific chromosome abnormalities are associated with prognosis in childhood acute lymphoblastic leukemia (ALL); however, chromosome abnormalities have not been evaluated for prognostic value in pediatric Burkitt and Burkitt-like lymphomas. For Children's Cancer Group protocol CCG-E-08 Etiologic Study of Non-Hodgkin Lymphoma in Childhood, 19 patients were enrolled with cytogenetic analysis of Burkitt or Burkitt-like lymphoma and simultaneously enrolled on treatment protocols CCG-503 or CCG-552. Pathology material and karyotypes at initial diagnosis underwent central review. Demographics included an age range of 2 to 14 years (median 8 years) and a male:female ratio of 14:5. All patients had advanced disease (stages III and IV, or ALL). Disease relapsed in five patients (event-free survival 74%, median follow-up 10.4 years). Chromosome abnormalities were identified in 18 patients (95%) including t(8;14)(q24.1;q32) in 12 (63%); t(8;22)(q24.1;q11.2) in 1 (5%); partial duplication of 1q in 7 (37%); and 13q32 abnormalities in 2 (11%). In patients who had relapses, in addition to the t(8;14)(q24. ;q32), two had abnormalities of 13q32 and two had partial duplication of 1q. CMYC translocations were absent in Burkitt-like lymphomas from all three patients. Burkitt and Burkitt-like lymphomas in children have a high frequency of chromosome abnormalities. Burkitt lymphoma abnormalities often involve CMYC translocations, usually a t(8;14)(q24.1;q32). Additional chromosome abnormalities that involved 13q32 and partial duplication of 1q were associated with poor prognosis. Burkitt-like lymphomas were not associated with CMYC translocations. Further studies are warranted in larger cohorts of children and adolescents with Burkitt and Burkitt-like lymphomas.