Malignant melanoma has a lower incidence than basal or squamous cell carcinomas, but is the most dangerous type of skin cancer due to the high capacity of metastasising. The main risk factor is sun exposure, although genetic predisposition is also involved. Early diagnosis realised through an excisional biopsy is very important because the cure rate depends on the stage of the disease. Proper surgical and adjuvant treatment lower the incidence of metastases and raise patient's survival rate. The article reviews the important aspects of malign melanoma from etiology to diagnosis, treatment and follow-up.