A patient with a variant form of acute promyelocytic leukemia (M3 variant) associated with an increased number of basophils was found to present a reciprocal translocation, t(9;14)(q34;q22) in addition to t(15;17)(q22;q12). Although several cases of acute nonlymphocytic leukemia with increased bone marrow and peripheral blood basophils have been reported, this is the first case in which both the t(9;14) and basophilia were observed in a patient with M3. Our findings support the hypothesis that 9q34 may be associated with the chromosomal location of genes regulating the production and maturation of basophils.