Denmark has had an organized screening programme for cervical cancer since the 1960s. In spite of this, almost 150 Danish women die from the disease each year. There are currently two different methods for preparation of cervical samples: conventional Papanicolaou smear and liquid-based cytology.In 2002, the Department of Pathology, Hvidovre Hospital changed over from the conventional Papanicolaou smear screening method to SurePath liquid-based cytology. This article is based on a retrospective comparison on data from the population screening programme for cervical cancer in the Municipality of Copenhagen.The number of tests with the diagnosis of "normal cells" decreased 1% after the conversion to liquid-based cytology, whilst the number of tests with "atypical cells" and "cells suspicious for malignancy" increased by 64.3% and 41.2% respectively. The number of tests which were "unsatisfactory for evaluation" decreased by 84%, whilst tests without endocervical cells increased by 8.2%. Comparison of follow-up histology showed more or less unchanged numbers of false positive samples.The data suggest that there is an increased detection rate of cervical precancerous lesions with liquid-based cytology. Follow-up histology showed no increase of false positive tests, whilst the share of tests which were "unsatisfactory for evaluation" decreased significantly. Overall, the liquid-based technique would seem to have several advantages compared to conventional smear.