The aim of dermatologic check-up is the early diagnosis of asymptomatic potentially dangerous skin changes. An early melanoma may be cured by simple excision. Dermatologic signs in general medicine are very important. Paraneoplastic symptoms in patients with glucagonoma consist of the typical necrolytic migratory erythema. Acrokeratosis Bazex is seen in patients with larynx carcinoma and dermatomyositis or acanthosis nigricans may occur in patients with internal malignancy. Spider angioma, jaundice, changes in hair pattern and white nails may be cutaneous signs of liver disease or necrobiosis lipoidica may be found in diabetic patients. Renal transplants and patients with HIV infection should be submitted for a dermatological check-up every six months. In these people several malignant tumors are seen more often than in control people.