Abstract The impact of multimodal prehabilitation on postoperative complications in upper abdominal surgeries is understudied. This review analyzes randomized trials on multimodal prehabilitation with patient and hospital outcomes. MEDLINE, Embase, CINAHL, and Cochrane CENTRAL were searched for trials on prehabilitation before elective (non-emergency) abdominal surgery. Two reviewers independently screened studies, extracted data, and assessed study quality. Primary outcomes of interest were postoperative pulmonary complications (PPCs) and all-cause complications; secondary outcomes included hospital and intensive care length of stay. A meta-analysis with random-effect models was performed, and heterogeneity was evaluated with I-square and Cochran’s Q test. Dichotomous variables were reported in log-odds ratio and continuous variables were presented as mean difference. Ten studies (total 1503 patients) were included. Odds of developing complications after prehabilitation were significantly lower compared to various control groups (− 0.38 − 0.75– − 0.004, P = 0.048). Five studies described PPCs, and participants with prehabilitation had decreased odds of PPC (− 0.96 − 1.38– − 0.54, P < 0.001). Prehabilitation did not significantly reduce length of stay, unless exercise was implemented; with exercise, hospital stay decreased significantly (− 0.91 − 1.67– − 0.14, P = 0.02). Multimodal prehabilitation may decrease complications in upper abdominal surgery, but not necessarily length of stay; research should address heterogeneity in the literature.