BACKGROUND: Malignant melanoma has an unpredictable biologic behavior and is the neoplasm with the greatest propensity for cardiac involvement. Although relatively frequent at autopsy, cardiac metastases are rarely identified antemortem. METHODS: We reviewed 2,810 patients with histologically confirmed malignant melanoma, who were diagnosed and followed up by our clinic. Clinical, histological, and imaging data are presented. RESULTS: Five cases of metastatic melanoma of the heart were identified out of 314 melanoma patients with visceral involvement. One case of a 53-year-old woman, who died unexpectedly during her first chemotherapy course, is described in detail. Postmortem examination determined the cause of death to be the presence of multiple melanoma metastases in the heart, even though the patient had shown no signs of cardiac involvement. CONCLUSIONS: The unpredictable biologic behavior of melanoma may lead to unusual metastatic sites, and, therefore, the heart also should be included in routine examinations