Malignant neoplasm arising in chronic, non-healing wounds has been known since ages and it was named Marjolin's ulcer about one hundred years ago. This scar malignancy arises in burned, constantly injured or chronically inflamed skin. Such pathologies as osteomyelitis, decubitus ulcers, chronic fistulas, frost bite, chronic venous failure, vaccination sites, skin graft donor sites and chronically traumatized skin are numbered among the etiological factors. Despite these numerous risk factors this oncological syndrome is rarely diagnosed and commonly mistaken, thus it may often be overlooked. Marjolin's ulcer may be defined by many pathological types of neoplasms. Squamous cell carcinoma (SCC) is the most commonly identified histological type followed by basal cell carcinoma (BCC), malignant melanoma, sarcomas (fibrosarcoma, liposarcoma, dermatofi-brosarcoma protuberans, mesenchymal tumor), mixed tumors: SCC-BCC, SCC-melanoma and others. There is an agreement over the prevention methods with skin grafting of burned areas and excision with simultaneous grafting of ulcerations appearing in non-healing wounds. To date, there has not been a consensus reached over the treatment protocol. Wide surgical excision seems to be the most preferred method. Inoperable cases and recurrences may be treated with radiotherapy alone or combined with chemotherapy.