Esophageal specimens derived from 60 patients with an established invasive squamous cell carcinoma of the esophagus were histologically surveyed with special reference to the morphological manifestations of human papillomavirus (HPV), known to cause flat, inverted and papillomatous lesions (Condylomas) in the uterine cervix. Epithelial changes fulfilling the criteria of the papillomatous condyloma were present in 1 case, those of the inverted lesions in 3 cases and those of the flat condylomas in 20 cases. The possible role of HPV in the development of these lesions was discussed, and the possibility was presented that HPV could be the agent responsible for or contributing to the evolvement of the esophageal squamous cell carcinoma in man.