Ten patients with malignant melanoma and phototoxic reactions under dacarbazine or 5-(3,3-dimethyl-1-triazeno) imidazole-4-carboxamide (DTIC) chemotherapy were investigated. All patients available for testing showed increased ultraviolet A-sensitivity (n = 5); patch testing revealed no type IV allergies (n = 6). In 5 patients intravenous DTIC was replaced by oral temozolomide, and no phototoxicity occurred. Temozolomide may represent an alternative for patients with DTIC-induced phototoxic skin reactions.