Five randomized pilot studies of screening for prostate cancer (PC) have been conducted in the area of Rotterdam from 1991 to 1994. The purpose of these studies was to establish the feasibility of a randomized screening protocol with PC mortality as the major end point in The Netherlands and at a European level. All procedures related to recruitment of participants, to application of the screening tests and to data collection were evaluated. Men (7,200) aged 55-74 years were invited through the Rotterdam Population Registry. The recruitment rate over the 5 pilot studies averaged 38.2% (2,747 men). Recruitment procedures proved to be relevant for establishing higher participation rates (invitation and consent by mail). The screening tests were well accepted and tolerated. The general population-based character of the sample was confirmed by studying symptoms of prostatic disease in participants and in men who refused participation. Data based on one PSA serum determination, rectal examination and transrectal ultrasonography are presented; 204/1,403 men (14.5%) had a positive screening result by either test combination and underwent biopsy. Forty-nine cancers were found in 1,403 men (3.5%); 65% of prostate cancers (17/26) identified in men who eventually underwent radical prostatectomy proved to be locally confined. From the pilot studies, we conclude that a large contribution to a European Randomized Study of Screening for Prostate Cancer (ERSPC) can be made by recruiting about 40,000 men in the area of Rotterdam. The preliminary data suggest that after confirmation of the present data during the first years in the European study, DRE and TRUS can be withheld depending on the PSA result in a large proportion of the screening population.