Object: Trends in incidence and mortality in the Nordic countries is part of the ongoing discussion concerning PSA screening for prostate cancer. This general discussion forms part one of this study and serves as a background for part two which is a cohort study describing prostate cancer incidence among Swedish and Danish immigrants in Norway compared with Norwegian men.Background: Prostate cancer incidence has had a relative increase of 67, 100, 120 and 241 percent in Denmark, Sweden, Norway and Finland respectively from 1970-2001. The fact that mortality from prostate cancer in Denmark is similar to the other countries may result from differences in tradition for opportunistic screening and early diagnostics. The evidence that early treatment influences mortality is still inadequate. The overdiagnosis and lead time resulting from screening are estimated to be substantial. Materials and Methods: Based on data from Cancer registry of Norway and Statistics Norway, Danish and Swedish males older than 35 years, born after 1930 and settled in Norway between 1965 and 2001 was selected. Standardized incidence rates(SIR) compared with the Norwegian population and confidence intervals was estimated by the indirect standardization method.Results: We found respectively six and fifteen cancers among 5463 Danish and 6529 Swedish men. SIR(Denmark) = 0,51(95%CI:0,19-1,12) and SIR(Sweden) = 1,34(95%CI:0,75-2,21). Discussion: The results were not statistically significant and therefore non-conclusive. However, the trends were similar to the national trends in incidence and this suggests that screening and early diagnostics not fully explains the differences between the Nordic countries.