Introduction: Although the number of cancer survivors has increased, the role of physical therapy in return to work (RTW) for employed patients with cancer remains unclear. Case presentation: The patient is a 50-year-old man diagnosed with cholangiocarcinoma who worked as a liquefied petroleum gas station filler. He started perioperative rehabilitation and underwent pancreaticoduodenectomy for cholangiocarcinoma. He developed a postoperative pancreatic fistula, which improved with conservative treatment over 40 days. Although he achieved independence regarding day-to-day activities, his physical condition and workability worsened, as his skeletal muscle index decreased from 8.7 to 7.7, 6-min walk distance from 518 to 460 m, and work ability index (WAI) from 37 to 20 points. His physical therapist was concerned about his RTW and recommended that he receive RTW support from the Department of Occupational Medicine (DOM). The DOM employed a team approach for the RTW strategy, and the primary physician, occupational physician, and company collaborated to support the patient. After the outpatient treatment protocol and RTW support plans were formulated, the patient was discharged. The physical therapist reported declining physical performance and WAI at the DOM’s multidisciplinary conference. After consulting with multiple professionals, the team recommended work resumption in stages: part-time for three months and full-time for four months after surgery while undergoing oral adjuvant chemotherapy. The WAI improved to 35 points after RTW. Conclusion: This case report suggests that physical therapists are vital in providing continuous patient support, from perioperative rehabilitation to DOM intervention, to build physical strength for return to work.