The combination of chromosomal translocations associated with bcl-2 rearrangement [t(14;18)] and c-myc rearrangement [t(8;14), t(8;22), or t(2;8)] has infrequently been detected in lymphoproliferative disorders. We have recently identified four cases of a B-cell malignancy exhibiting this dual translocation. In addition to t(14;18), one case had t(8;14) and three had the t(8;22). One case presented as de novo acute lymphoblastic leukemia (ALL-L2), two as de novo high grade lymphomas and the fourth evolved to a "blastic" phase from a previously documented follicular lymphoma. Immunophenotyping and molecular analysis was performed on three of the cases: all were negative for terminal deoxynucleotidyl transferase (TdT) but were CD10 positive. Two of the three cases with t(8;22) were negative for surface immunoglobulin (SIg) and positive for HLA-DR. Rearrangement of the oncogene bcl-2 was identified in a single case by polymerase chain reaction (PCR) only. Similar to cases reported in the literature, all patients had a poor clinical outcome despite aggressive therapy. Dual translocation lymphoid malignancy has a relatively characteristic morphology and the diagnosis should be considered when there is a history of an antecedent low grade lymphoma or when there is discordance between the "blastic" morphology and the immunophenotype (TdT- and/or SIg+). Confirmation requires demonstration of the characteristic translocations. Recognition of this entity has significant clinical implications that may require consideration of alternate treatment strategies.