11q13 translocation has been described in mantle cell lymphoma in the form of t(11;14) (q13;q32), with rearrangement and over-expression of the cyclin D1 gene. Recently, an association between 11q13 and acute myeloid leukemia is recognized. We describe the occurrence of 11q13 translocations in both acute leukemias and myelodysplastic syndrome, and suggest that other genetic mechanisms unrelated to cyclin D1 may be involved in the tumorigensis. Furthermore, 11q13 appears to be a cytogenetically promiscuous site involved in reciprocal translocations with different chromosomes in both myeloid and lymphoid malignancies.