This article reports the results of a clinicopathologic study of 44 keratoacanthomas of the eyelid. This tumor characteristically has a rapid development and presents as a hemispherical elevated lesion with a keratinfilled central crater. There is some predilection for the lower lid. Clinically the lesion is most often confused with basal cell carcinoma, but it may resemble a variety of other epithelial tumors. In the past keratoacanthoma has often been clinically and pathologically interpreted as squamous cell carcinoma. The lesion is benign, and although it may undergo spontaneous regression, we feel that simple excision at an early stage is the treatment of choice in most cases. The pathogenesis is not established.