The aim of this study was to estimate uptake of PSA testing in an entire country, including time trends and geographical differences. Data from the Swedish Cancer Register on prostate cancer incidence between 1980 and 2007 and published data from the Gothenburg branch of the European Randomized Study of Screening for Prostate Cancer (ERSPC), a population-based PSA screening study, were used in a multiplicative model of changes in incidence of prostate cancer as a proxy for uptake of PSA testing in all 24 Swedish counties. The estimated PSA testing in any one year, irrespective of previous years' exposure, reached a peak of 12% of all men in 2004 and decreased thereafter to 6% in 2007 and varied between 5% and 20% between counties. Under the assumption that men who underwent PSA testing were previously unexposed to PSA testing, the cumulated uptake of PSA testing in men aged 55-69 years in Sweden increased from zero in 1997 to 56% in 2007. This study shows that it is possible to estimate uptake of PSA testing in the population from the prostate cancer incidence pattern. There were large geographical variations in uptake of PSA testing despite a uniform health care system in Sweden and there was a substantial increase in the uptake of PSA testing during the study period, despite that there were no national recommendations for PSA-based prostate cancer screening.