Purpose The aim of this systematic review is to provide an update on the effects of resistance exercise (RE) in patients with prostate cancer (PCa), with special attention to the effects on sexual health. Methods A systematic search of the literature was conducted in March 2020 using the databases PubMed, MEDLINE, EMBASE, SCOPUS and the Cochrane Library. Only randomized, controlled trials published after 31 December 2016 were included in this update. Additionally, articles from current and previous reviews were utilized to provide a brief summary of the effects on sexual health. Results A total of 10 articles met the inclusion criteria, of which 5 were identified as independent studies. The remaining five articles presented additional data for studies, which have already been included. The identified studies further strengthened the evidence for positive effects on muscle strength, body composition and physical function. Positive effects on bone mineral density were apparent only when RE was combined with impact training. One article reported an improvement in fatigue and health-related quality of life. Only one study examined the effects of RE in isolation and three articles indicated positive effects of exercise on sexual health. Conclusion Recent evidence supports the use of RE in PCa patient rehabilitation as a countermeasure for All authors are employees of the Medical University of Vienna, Austria, and the preparation of this review took place within the scope of their regular scientific work.