Under the title superficial epitheliomatosis1 is included the clinical picture that has also been described under the terms erythematoid benign epithelioma,2 multiple superficial basal cell epithelioma of the trunk, multiple superficial benign epithelioma of the skin,3 carcinoid of the skin, Bowen type epithelioma, pagetoid epithelioma, carcinoma cutis multiformis and variations of these titles. The term superficial epitheliomatosis is chosen because I believe it is the most concise and accurate description that can be applied to the entity. The multiplicity of titles mentioned has caused confusion which has been increased by the failure of some authors to distinguish this disease from Bowen's precancerous dermatosis or from the extramammary type of Paget's disease. It will be shown that superficial epitheliomatosis is frank basal cell, basal squamous cell or squamous cell epithelioma, occurring usually on the trunk. These epitheliomas will be distinguished from (1) certain benign types of dermatosis, (2)