Skin melanoma is a malignant lesion in the skin. It is often located on the head, neck, legs, back, mouth, anus and in the eye. It is an asymmetric tumour, flat or slightly raised, with irregular borders. It may bleed or itch. The risk factors are excessive esposure to UV rays, pale complexion, moles, radiation treatment, family history of melanoma and living in hot areas. It needs surgical excision, because it can cause metastases. The prognosis depends on the depth and thickness of tumor.