Testicular infiltration is a well-known complication in acute lymphoblastic leukemia. In acute myeloid leukemia (AML), it has rarely been described and preferably occurred in cases with myelomonocytic or monoblastic differentiation. We report on a patient with AML with complex karyotype including translocation t(8;21) who presented with testicular infiltration at the time of his third bone marrow relapse. Cytological analysis of the specimen showed infiltration with blasts displaying the typical morphology of AML with translocation t(8;21) and comparable to those detected in the bone marrow. Fine needle aspiration cytology might suffice in these cases and should be performed if testicular involvement is suspected.