Skin reactions are common in the workplace. The skin, which constantly is exposed to chemicals and industrial processes, develops inflammatory reactions, most commonly dermatitis, which may have an allergic or irritant basis. The epidemiology, pathophysiology, and clinical features of common occupational dermatoses are discussed. Irritant, allergic, and urticarial contact reactions are compared, and their clinical features are outlined. Important occupational irritants and allergens, their sources, and the industries in which they most commonly are found are listed. The prognosis and therapy of these occupational reactions are examined.