Background <p>The All-on-4 implant technique offers an effective rehabilitation solution for maxillary bone - deficient patients, yet preventing and controlling complications in those with severe periodontitis and Parkinson’s disease (PD) poses a clinical challenge. </p> Case presentation <p>A 63-year-old PD patient had multiple teeth extracted due to mobility years ago and a history of failed implant rehabilitation in the posterior maxilla at another hospital. He was diagnosed with dentition defect and chronic periodontitis upon admission. Immediate All-on-4 implant rehabilitation was performed after extraction of the remaining maxillary teeth. Three months postoperatively, implant at site 15 became loose and was removed; three months later, tilted implantation was performed at site 15, and simultaneous maxillary sinus floor elevation with implant placement was conducted at sites 16 and 17. Six months after the second operation, implant 25 failed and was extracted; two months later, tilted implantation was re-performed at site 25, and simultaneous maxillary sinus floor elevation with implant placement was carried out at sites 26 and 27. Final fixed prosthodontics was completed, and during the 55-month follow-up, the prosthesis has remained stable, and masticatory function has been significantly improved compared with the pre-treatment status.</p> Conclusion <p>This case report firstly presents a complication management protocol following All-on-4 rehabilitation in patients with PD. For PD patients complicated with severe maxillary bone deficiency and concurrent periodontitis, All-on-4 rehabilitation mandates rigorous preoperative periodontal treatment, individualized implant site design, reliable patient compliance, and standardized periodic postoperative maintenance. Dentists should stay alert to potential obstacles to oral self-care and xerostomia in PD individuals.</p>