We examined the presence of human papillomavirus (HPV) DNA in 65 cases of laryngeal squamous dysplasia and carcinomas using in situ hybridization with signal amplification in paraffin sections. Hybridization was performed with biotinylated DNA probes for HPV 6/11, 16/18, 31/33 and wide-spectrum HPV (6, 11, 16, 30, 31, 45, 51 and 52). HPV DNA was found in 7 cases of the total sample (10.7%); it was also found in 4 out of 45 (8.8%) cases of invasive carcinoma and in 5 out of 33 (15.5%) cases of squamous dysplasia. Morphological signs suggestive of HPV infection were observed in 35.5% of our sample but they were not related to HPV DNA positivity. In conclusion, HPV probably plays little, if any, role in laryngeal carcinogenesis among the population studied.120540-4