Prostate cancer prognosis may be improved by maintaining healthy weight through healthy behaviours, particularly diet and physical activities. We carried out a systematic review to identify the successful components and mode of delivery of weight management interventions in this group. MEDLINE, EMBASE, CINAHL and the Cochrane Library databases were searched from the earliest record to August 2012. Randomised controlled trials with dietary and exercise intervention components which involved prostate cancer patients were included. A total of 20 studies were included. Interventions were categorized as dietary(n=6), exercise (n=8) or combination of both dietary and exercise (n=6) interventions. All studies were published within the last ten years with the majority of the studies were conducted in North America. The sample size ranged from 8-155 and the period of intervention varied from three weeks to four years. Only four dietary intervention studies, two exercise intervention studies and two combination intervention studies achieved significant weight loss or body composition improvement. We conclude that there is no clear evidence of the best intervention components and delivery to be recommended but low fat diet seems to be the important component of healthy weight maintaining programme. Future RCTs should use larger samples with more specific focus on weight or anthropometric changes to avoid recurrence and improve overall survival in long term.