A metastatic malignant melanoma in a 54-yr-old white female was examined cytogenetically on three different occasions. We found two different clones, one hypodiploid and another hypertriploid; however, both clones had the same markers [i.e., der(6),t(6;17), and der(17),t(1;17)]. Detailed analysis of the histopathology and clinical course suggests that these two different clones reflected different morphology and results of therapy.