A patient with B-cell lymphoma with a chromosome rearrangement of t(14;19)(q32.3;q13.1) is reported. This patient had leukemic features and an aggressive clinical course. The histopathologic diagnosis was malignant lymphoma, small noncleaved cell. Chromosome analysis of the cells from a cervical lymph node and peripheral blood showed a reciprocal translocation between chromosome 14 with a break at band q32.3 and chromosome 19 with a break at band q13.1, to which the bcl-3 gene has been mapped. Monoclonal rearrangement of the JH gene was detected by Southern blot analysis. However, we could not detect rearrangement of the bcl-3 gene. This case also had a t(2;8)(q13;q24.1), but the c-myc gene remained in its germline. This is the first case with the reciprocal t(14;19) and 8q24 chromosomal breakpoint in a B-cell lymphoid malignancy.