Context: Androgen-replacement therapy (ART) is a widely accepted form of treatment worldwide for aging men with late-onset hypogonadism syndrome. Urologists have been concerned about the possibility of ART causing prostate growth. Objective: To assess the relationship between ART and prostate growth. Evidence acquisition: A literature review was performed to identify all published randomized controlled trials (RCTs) of androgen treatment for hypogonadism. The search included the Medline, Embase, and Cochrane Controlled Trials Register databases. The reference lists of the retrieved studies were also investigated. A systematic review and meta-analysis were conducted. Evidence synthesis: Results of 16 RCTs involving a total of 1030 patients were analyzed. Seven RCTs were short-term (<12 mo) and nine were long-term (12-36 mo) comparisons of ART with a placebo; ART was administered transdermally, orally, or by injection. Respective p values for injection, transdermal administration, and oral administration of short-term ART were as follows: PSA level: 0.07, 0.01, and 0.95; prostate volume: 0.70, 0.79, and 0.32; IPSS: 0.78, 0.98, and no oral; Q(max): 0.92, no transdermal, and 0.10. Respective p values for injection, transdermal administration, and oral administration of long-term ART were as follows: PSA level: 0.42, 0.51, and 0.57; prostate volume: 0.35, 0.59, and 0.47; IPSS: 0.34, 0.32, and 0.97; Q(max): 0.11, 0.63, and no oral. Neither short-term nor long-term ART showed significant changes in the four determinants of prostate growth investigated compared with placebo. Conclusions: This meta-analysis shows that regardless of the administration method, neither short-term nor long-term ART increases the risk of prostate growth. Further high-quality, prospective studies are required to confirm this observation. (C) 2013 European Association of Urology. Published by Elsevier B.V. All rights reserved.