Background and Objectives: Although the growing literature is now focusing on the long-term effects of Deep Brain Stimulation (DBS) in Parkinson’s disease (PD), there is still a large gap of knowledge about its long-term implications in rehabilitation. Therefore, this study aimed at investigating the effects of rehabilitation in PD patients years after DBS implantation. Materials and Methods: This retrospective case–control study analyzed records from Moriggia-Pelascini Hospital, Italy from September 2022 to January 2024. Data of PD patients (n = 47) with (DBS group, n = 22) and without (control group, n = 25) DBS were considered. All study participants underwent a daily rehabilitation program lasting four weeks, including warm-up, aerobic exercises, strength training, postural exercises, and proprioceptive activities. The outcomes assessed were the Unified Parkinson’s Disease Rating Scale (UPDRS), Berg Balance Scale (BBS), Timed Up and Go (TUG), 6 Min Walk Test (6MWT), and Self-Assessment Parkinson Disease Scale (SPDDS). Results: DBS group showed significant improvements in terms of all outcome measures after the rehabilitation intervention (UPDRS III: −7.0 (−11.5 to −1.0); p = 0.001; UPDRS I II IV: −12.0 (−19.0 to −4.5); p = 0.001; BBS: 7.0 (3.8 to 10.3); p < 0.001; TUG (s): −2.8 (−5.7 to −1.1); p < 0.001; SPDDS: −8 (−13.0 to −4.0); p < 0.001; 6MWT (m): 81 (37.3 to 132.3); p < 0.001). No differences were reported in the between-group analysis (p: NS). Conclusions: This study emphasizes positive rehabilitation effects on PD patients irrespective of DBS status. Further research is essential to elucidate long-term effects of DBS on rehabilitation outcomes of PD patients.