To investigate the association of human papillomavirus with conjunctival neoplasia, we identified 50 resected papillomas from 47 patients. Papillomas were composed of papillary or, less commonly, flat proliferations of predominantly nonkeratinizing squamous epithelium with admixed goblet cells. Koilocytosis was focally present in 30 tumors (60%). Atypia that ranged from mild to severe was present in ten lesions (20%). In addition, we examined specimens of conjunctival dysplasia or carcinoma from 61 patients. The lesions were predominantly flat proliferations of atypical epithelial cells. Twenty biopsies performed for suspected sarcoidosis were used as controls. Papillomavirus capsid antigen was demonstrated using an immunoperoxidase technique in nuclei of mature superficial epithelial cells of 23 papillomas (46%) and five dysplasias or carcinomas (8.2%) but not in the control biopsy specimens. These results suggest that papillomavirus may play a role in the etiology of conjunctival papilloma, dysplasia, and carcinoma.