The study aimed at probing the possible role of human papillomavirus (HPV) infection in squamous cell carcinomas of the upper aerodigestive tract, with a special reference to tonsillar cancer. We used the Swedish Family Cancer Database to analyse second cancers in the upper aerodigestive tract of women first diagnosed with in-situ or invasive cervical cancer. First cancers of their husbands were also analysed. Standardized incidence ratios (SIRs) were calculated for female and male cancers, adjusted for age at diagnosis, period, sex, socio-economic status and residential area. Among women, increases were observed at many sites, but tonsillar cancers were increased only among women aged 50 years or more at diagnosis of in-situ cervical cancer (SIR 2.58). The increases at these sites are probably ascribed to the effects HPV, smoking, alcohol or their interaction. Husbands of cervical cancer patients developed an excess (SIR over 2.00) of both tonsillar cancer (SIR 2.39 when wife with in-situ cancer and SIR 2.72 when wife with invasive cervical cancer) and cancer of the tongue. The excess of tonsillar cancer among husbands of women with HPV-associated neoplastic lesions of the cervix supports the a priori hypothesis that HPV may be involved in tonsillar carcinogenesis.