Human papillomavirus types HPV 16 and HPV II DNA sequences were analyzed in normal and neoplastic tissues of the larynx, using the technique of polymerase chain reaction (PCR). An amplified region of E6 ORF was hybridized with 3′ end-labelled oligonucleotide probe. Twenty six out of 48 (54%) squamous-cell carcinomas, and 3 out of 3 verrucous-cell carcinomas hybridized with HPV 16 DNA sequences, whereas we did not detect HPV II sequences. HPV 16 DNA sequences were also found in normal, autologous mucosa and lymphnode metastases, although these were absent in other tissues analyzed. HPV-16-positive tumors were most frequently poorly differentiated squamous-cell carcinomas.