The purpose of this atlas, which collects over 900 clinical and histological photographs in high resolution, is to illustrate and describe the most frequent skin diseases on the basis of clinical cases. Offering a complete guide to the etiology, epidemiology, clinical features, histologic findings and diagnosis of the main skin diseases divided into three subgroups (inflammatory, infectious, or tumoral), it represents an invaluable resource for all medical students, residents, clinicians, and investigators learning dermatology.