Prehabilitation benefits among patients undergoing various oncological surgeries have been demonstrated. However, the effects of presurgical exercise and fitness on postoperative ipsilateral upper extremity recovery outcomes in patients with breast cancer surgery are less evident. A systematic review was performed to assess the effects of preoperative exercise and fitness on postmastectomy recovery. Systematic literature search was performed in 12 electronic databases. Study eligibility was accessed using the PICOS (Participants, Interventions, Comparison, Outcome and Study Design) criteria. Six eligible studies were found: three cohort–control and three prospective observational studies. One randomized-controlled trial showed that prehabilitation was beneficial in shoulder range of motion (ROM) and upper extremity functional recovery. One cohort–control study demonstrated that preoperative exercises reduced postoperative pain without increasing the risk of developing a seroma. A prospective cohort study showed that preoperatively active individuals had a significantly better chance of feeling recovered physically at 3 weeks after surgery. Baseline ipsilateral grip strength, shoulder flexion, and abduction ROM were reliable predictors of shoulder flexion and abduction ROM and grip strength improvements at 1 month following breast cancer surgery. One study showed that preoperative conditioning alone without postoperative rehabilitation was insufficient to aid recovery. Implementing exercise program and optimizing preoperative fitness, especially shoulder ROM, before breast cancer surgery in conjunction with individualized rehabilitation program may benefit postmastectomy ipsilateral upper extremity recovery.