Melanoma is a malignant tumor of melanocytes that has tendencies to metastasize both lymphatic and hematogenous. The increasing numbers can be seen in all countries of the world. People with lighter skin that have been exposed to the sun are the ones who are affected by this kind of skin cancer. Melanoma occurs on the intact skin or from nevi. The biggest malignant potential have people with giant congenital and dysplastic nevi. Melanoma is dark colored that varies from brown to black but there are some that have no pigment. Melanoma has three stages of growth: melanoma in situ (it indicates the phase where the malignant melanocytes occur in basal layer of the epidermis), radial stage (indicates the phase of lateral expansion) and vertical stage (phase of dermis invasion). According to clinical characteristics and histological grade we can differentiate lentigo melanoma (melanoma in situ), LLM (lentigo maligna melanoma), SSM (superficial spreading melanoma), NM (nodular melanoma) and ALM (Acral Lentiginous Melanoma). Most frequent is the SSM which occurs on the backs of men and on lower extremities in women. Clinical signs that indicate melanoma are asymmetrically shaped, irregular, with jagged or ridged edges. Color can vary from darker shade of brown to lighter brown or yellow. They are usually bigger than 6 mm.Prognosis is connected with degrees of skin invasion (Clark), the thickness of tumor (Breslow) and its growth stage. First stage – primary tumor without metastasis life rate of 5 years is 75%, second stage – primary tumor with metastasis in regional lymph knots is 25%, and third stage – distant metastasis 0%. All rest unfavorable prognostic factors are ulcerated tumor, regression of part of tumor, enlarged number of mitosis, microsatellites, older age and male gender. Therapy is always radical surgery that cuts 1 to 3 cm in healthy tissue. It can also be treated by dissection of sentinel knot if metastasis are comformed. The most important is the prevention, protection from UV.