Malignant wounds are atypical wounds that are the result of malignant tumor itself, cutaneous metastases of remote malignant process, or are part of the paraneoplastic syndrome. Malignant skin tumors that can result in ulcer are melanoma, squamous cell carcinoma and basal cell carcinoma. Basal cell carcinoma is the most common malignant skin tumor with an increasing incidence. Numerous malignant tumors can metastasize to the skin, with melanoma being the leading cause of cutaneous metastases (40 percent of all skin metastases). When treating persisting chronic wound without expecting healing progress, it is obligatory to perform biopsy with histopathologic analysis in order to exclude malignant process (basal cell carcinoma, squamous cell carcinoma, melanoma, especially acral-lentiginous melanoma on distal parts of extremities, which often ulcerates and is amelanotic, or Kaposi sarcoma). Delay in the diagnosis of a malignant wound may result in poorer prognosis, loss of the affected limb or the occurrence of metastases.