A series of 10 oesophageal and 10 laryngeal squamous carcinomas was examined by means of immunocytochemistry and in situ DNA hybridisation to demonstrate human papillomavirus (HPV) infection. Changes in the epithelium adjacent to the carcinoma were found in 5 of 10 oesophageal and 7 of 10 laryngeal carcinomas. Viral antigens could not be detected with immunocytochemistry in any of the specimens. HPV 6, 11 and 16 were detected in 3 oesophageal specimens. In one of these, HPV 16 was detected in normal as well as malignant cells. HPV 7 was detected for the first time in a laryngeal carcinoma. Our results confirm previous reports of possible HPV involvement in the pathogenesis of aerodigestive carcinomas.