In Greenland, the incidence of cervical cancer is 5.7 times higher than in Denmark among women aged 20-39. From Nuuk (Greenland) and Nykøbing Falster (Denmark) a sample of 800 women aged 20-39 years was drawn at random. A total of 586 and 661 women were investigated in Greenland and Denmark respectively. All women had a gynecological examination including a PAP-smear and cervical scrape for HPV-analysis (filter in situ hybridization). A blood sample was taken for analysis of HSV type-specific antibodies (ELISA). The percentage of normal smears was identical in the 2 areas (95%). The total HPV 16/18 infection rate was 13% in Denmark and 8.8% in Greenland, and the age-adjusted prevalence rate in Greenland was only 67% of that in Denmark (95% CI: 0.05-0.89). The proportion of HPV 6/11 positivity was the same in Greenland and in Denmark (6.7% vs. 7.5%). A significantly higher proportion of the Greenlandic women had HSV-2 antibodies (68.2%) in comparison with Danish women (30.9%) (p less than 0.01). The prevalence of HSV-1 was also higher in Greenland, especially in women aged 20 to 24. Our finding of a higher HPV infection rate in Denmark than in Greenland, opposed to cervical cancer rates, does not support a role for these viruses as determinants of cervical cancer incidence. In contrast, the rate of HSV-2 infection co-varies with the observed incidence of cervical cancer. This is in line with the notion that differences in cervical cancer incidence between Denmark and Greenland are determined by aspects of sexual behavior.