Objective: This is the first of two review papers attempting to clarify the best way to detect prostate cancer (PCa) in 2007. Screening for PCa has not yet been shown to lower PCa mortality. Still, opportunistic screening is wide spread in Europe and in most other parts of the world. Methods: Current literature and data from screening studies are reviewed and discussed. Prostate-specific antigen (PSA) has been and remains one of the corner stones of early detection of PCa. Traditionally used cut-off values cannot be applied in an uncritical fashion after it was shown that a significant amount of overdiagnosis and that large proportions of cancers and poorly differentiated cancers are present in the low PSA ranges. The paper addresses the continued relevance of PSA cut-off values. The diagnostic value of PSA velocity is reviewed in conjunction with PSA cut-off values and as a possible replacement of total PSA. A need for more selective screening in the low PSA ranges is pointed out. Results and conclusions: The data show that men presenting initially with PSA values below I do not have to be rescreened for a period of 8 yr. In the PSA range 1-2.9 ng/ml, new parameters are needed that improve specificity and are selective for screening for aggressive lesions. PSA velocity so far has not been shown to be useful in the early detection of PCa but may be useful in detecting aggressive PCa selectively. For the time being, it seems sensible to continue using PSA cut-off values such as 3.0 or 4.0 ng/ml provided overtreatment is decreased by using available nomograms. (C) 2007 European Association of Urology. Published by Elsevier B.V. All rights reserved.