Background: Exercise and nutrition-based prehabilitation programs are promising emerging strategies for enhancing surgical recovery. However, prior studies have reported mixed findings regarding their impact on postoperative outcomes. The purpose of this study is to investigate the efficacy of exercise and nutrition-based prehabilitation on postoperative outcomes, including length-of-stay (LOS), complications, quality-of-life (QoL), pain, and mental health. Methods: A systematic review and meta-analysis was conducted, using MEDLINE, Cochrane Central, EMBASE, and Web of Science, following PRISMA guidelines. Studies published between 2004 and 2024 were identified with search terms including “prehabilitation,” “exercise,” “nutrition,” and “surgery.” Eligible studies (n=293) were randomized controlled trials (RCTs) evaluating exercise or nutrition-based prehabilitation programs and reporting LOS and complications as primary outcomes. Secondary outcomes included QoL, pain, and mental health scores. Random-effects meta-analyses estimated pooled effect sizes. Results: 23 RCTs were included (2,182 participants). Exercise or nutrition-based prehabilitation reduced complications (odds ratio (OR) 0.52. 95% confidence interval (CI):0.35,0.78, p<0.002, I 2 =47.1%) and LOS (mean difference (MD) -0.44 days, 95% CI:-0.78,-0.11, p=0.01, I 2 =44.8%) compared to standard treatment. When comparing interventions, nutrition only had a greater reduction in LOS than exercise only (MD -1.09 days, 95% CI:-1.72,-0.47 vs. MD -0.20 days, 95% CI: -0.51, 0.09; p=0.01). While QoL was not reported in nutrition only RCTs, exercise alone improved QoL measures (standardized mean difference 0.94, 95% CI: 0.24,1.64, p=0.01, I 2 =93.6%) compared to standard treatment. Conclusion: Exercise or nutrition-based prehabilitation programs reduce LOS and complications across multiple surgical contexts. Further work is needed to elucidate the impact of different intervention protocols and their impact on postoperative outcomes.