With the aim to assess the prevalence and the main clinical correlations of skin lesions in diabetes mellitus, 457 diabetic subjects consecutively attending an outpatient clinic underwent a dermatological examination. Neurovascular foot lesions were excluded. Thirty-five of 64 IDDM patients (54%) had skin alterations mainly consisting of vitiligo (9% of all patients), psoriasis (9%) and eczema (8%). The most frequent skin lesions observed in 240/393 NIDDM subjects (61%) were represented by infections (20% of all patients) and diabetic dermopathy (12.5%), while other lesions were not common. NIDDM patients with skin infections had a worse metabolic control, and those with diabetic dermopathy had a greater prevalence of neuropathy and large vessel disease than patients without skin lesions. These data show that the prevalence of skin diseases in a large, unselected diabetic population is higher than expected and indicate that, in most cases, a careful dermatological examination and a better metabolic control are needed in order to improve quality of life in these patients.