Prostate cancer is the most common carcinoma of elderly males and holds the third place in the ranking of cancer-specific mortality. However, total mortality rate of 3 % is low and half of the patients die from other diseases, which is for the most part due to significantly improved diagnostic methods and the increasing use of prostate-specific antigen (PSA) screening. This has led to a stage migration towards early tumor stages that are prognostically heterogeneous and require differentiated treatment. The German and European guidelines recommend four therapy options (i.e. radical prostatectomy, percutaneous irradiation, permanent seed implantation and active surveillance) for localized prostate cancer and from contemporary study data it is unclear which therapy is most beneficial. This will be the subject of the PREFERE trial, a prospective randomized multicentre trial which plans to recruit 7,600 patients and to observe them over a period of up to 17 years. The histopathological diagnosis of the primary biopsy plays a crucial role in the inclusion criteria, as this article outlines in detail.