Human papillomaviruses are receiving attention for their role in the pathogenesis of cancer, especially cancer of the anogenital tract. Although strains of human papillomavirus are associated with benign lesions of the conjunctiva, their association with conjunctival dysplastic lesions and carcinomas has remained unclear. We examined a group of neoplastic lesions of the conjunctiva for the presence of DNA sequences for human papillomavirus types 16 and 18, using in vitro gene amplification with the polymerase chain reaction. Tissue specimens of five conjunctival dysplastic lesions and one invasive carcinoma and swab specimens of the mucosa of both corneas of a patient with unilateral corneal dysplasia contained DNA sequences related to human papillomavirus type 16. All dysplastic specimens examined were positive for DNA sequences. Viral DNA was not detected in six control specimens from patients with conjunctival melanoma, papilloma, nevus, or pterygium. We conclude that DNA from human papillomavirus type 16 is present in a substantial percentage of conjunctival premalignant and malignant lesions. It may play a part in the development of conjunctival dysplasia and carcinoma, as it does in cancers of certain other body sites.