The 3q21q26 inversion is associated with both myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), often in association with monosomy 7. In this report, we present a young woman and her mother, both diagnosed with AML, exhibiting similar morphological and identical cytogenetic features. AML with abnormalities of chromosome 3q is often characterized by abnormal megakaryopoeisis and diabetes insipidus, and both were seen in these cases. To our knowledge, this is the first report of familial aggregation of AML displaying an inversion of chromosome 3q and monosomy 7. We discuss possible mechanisms for the development of familial AML with identical karyotypic abnormalities and the link between 3q aberrations and monosomy 7.