Six European, randomized, controlled trials that will compare human papillomavirus (HPV) testing with cytological testing for cervical screening are under way. We reviewed the results published so far to compare the benefits and costs for participating women. At baseline screening, use of HPV testing increased the detection of cervical intraepithelial neoplasia (CIN) grade 2+. Detection of CIN3+ was significantly increased in two trials (relative risks [RRs] 1.70 and 2.26), but not in three other trials (RRs 1.03, 1.09 and 1.31). In three trials, seven extra women had a false-positive test for each extra detected CIN2+ case; although, in another trial, this number was 49 in women > or =35 years of age. The outcome of HPV testing versus cytological testing depends not only on the relative accuracy of the primary test but also on how radical the different triage procedures are. In two trials with published outcomes from the subsequent screening round, an approximately 50% reduction in CIN3+ detection was evident in the subsequent screening. However, in these two trials the screening modalities changed between the baseline and subsequent screening rounds, so these data do not show the effect of a switch from primary screening with cytological testing to primary screening with HPV testing.