Often contraindicated because of the theoretical risk of progression based on the dogma of hormone dependent prostate cancer (CaP), testosterone replacement therapy (TRT) is increasingly discussed and proposed for hypogonadal patients with localized CaP. To perform a systematic literature review to determine the relationship between TRT and the risk of CaP with a focus on the impact of TRT in the setting of previous or active localized CaP. As of October 15, 2019, systematic review was performed via Medline Embase and Cochrane databases in accordance with the PRISMA guidelines. All full text articles in English published from January 1994 to February 2018 were included. Articles were considered if they reported about the relationship between total testosterone or bioavailable testosterone and CaP. Emphasis was given to prospective studies, series with observational data and randomized controlled trials. Articles about the safety of the testosterone therapy were categorized by type of CaP management (active surveillance or curative treatment by radical prostatectomy, external radiotherapy or brachytherapy). Until more definitive data becomes available, clinicians wishing to treat their hypogonadal patients with localized CaP with TRT should inform them of the lack of evidence regarding the safety of long-term treatment for the risk of CaP progression. However, in patients without known CaP, the evidence seems sufficient to think that androgen therapy does not increase the risk of subsequent discovery of CaP.