BackgroundFibrous dysplasia of bone (FD) is a rare skeletal disorder. Traditional surgical options may have disadvantages such as greater trauma, incomplete curettage and recurrence risk. In this report, we introduce the technique for the treatment of fibrous dysplasia of the femur with Arthroscopic-assisted uni-portal non-coaxial endoscopic surgery (AUNES) and evaluate its feasibility.Case presentationWe described a 49-year-old female patient with an elliptical lesion measuring approximately 4.3 cm x 4.2 cm in the proximal left femur. Due to the limitations of traditional open surgery-significant trauma, incomplete curettage, and a high risk of recurrence-we performed tumor curettage and bone graft fusion with AUNES assistance for the first time. The AUNES endoscopy provided a clear surgical field, precise lesion boundaries, thorough curettage, and minimal blood loss. Postoperative pathology confirmed fibrous dysplasia. At the 1-month and 3-month postoperative follow-ups, the patient's surgical wound healed well without complications. DR and CT scans showed satisfactory graft placement and bone fusion.ConclusionThis case report demonstrates that AUNES-assisted tumor lesion curettage and bone grafting fusion surgery for FD is safe and feasible. It offers several advantages, including minimal invasiveness, a wide surgical field, thorough lesion curettage, and a low postoperative recurrence rate.