Context: Prostate cancer screening is highly controversial, including the age to begin prostate-specific antigen (PSA) testing. Several studies have evaluated the usefulness of baseline PSA measurements at a young age. Objective: Review the literature on baseline PSA testing at a young age (<= 60 yr) for the prediction of prostate cancer risk and prognosis. Evidence acquisition: PubMed was searched for English-language publications on baseline PSA and prostate cancer for the period ending April 2011. Evidence synthesis: In most published series, median PSA levels in the general male population range from approximately 0.4 to 0.7 ng/ml in men in their 40s and from approximately 0.7 to 1.0 ng/ml in men in their 50s. Evidence from both nonscreening and screening populations has demonstrated the predictive value of a single baseline PSA measurement for prostate cancer risk assessment. Specifically, men with baseline PSA levels above the age-group-specific median have a greater risk of prostate cancer diagnosis during the next 20-25 yr. Additional studies confirmed that higher baseline PSA levels at a young age are also associated with a greater risk of aggressive disease, metastasis, and disease-specific mortality many years later. Conclusions: Baseline PSA measurements at a young age are significant predictors of later prostate cancer diagnosis and disease-specific outcomes. Thus baseline PSA testing may be used for risk stratification and to guide screening protocols. (C) 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.