Objective To summarize the effectiveness of acetabulum reconstruction with autologous femoral head structural bone graft in total hip arthroplasty (THA) for Hartofilakidis type Ⅱ developmental dysplasia of the hip (DDH). Methods A clinical data of 24 patients (27 hips) with Hartofilakidis type Ⅱ DDH, who underwent acetabulum reconstruction with autologous femoral head structural bone graft in primary THA between October 2012 and October 2020, was retrospectively analyzed. There were 3 males and 21 females, with an average age of 40 years (range, 20-58 years). The body mass index was 19.5-35.0 kg/m² with an average of 25.0 kg/m². There were 21 cases of unilateral hip and 3 cases of bilateral hips. The hip Harris score was 51.1±10.0. The leg length discrepancy of unilateral hip patients was (19.90±6.24) mm. The intraoperative blood loss, wound healing, and complications were recorded. The postoperative bone union, coverage rates of acetabular prosthesis and bone graft, and aseptic loosening of the prosthesis were evaluated based on X-ray films, and the improvement of hip function was observed by Harris score. Results The intraoperative blood loss was 50-1000 mL (median, 350 mL). All incisions healed by first intention, and no fracture, hematoma, infection, or other complications occurred. Sciatic nerve injury occurred in 1 case (1 hip) and deep venous thrombosis occurred in 1 case (1 hip). All patients were followed up 15-103 months (median, 40.5 months). At last follow-up, Harris score was 92.6±4.1 and the difference was significant when compared with preoperative value (t=−28.043, P=0.000). No hip prosthesis needed revision. X-ray films showed that the coverage rate of acetabular prosthesis was 91%-100% (mean, 97.8%), and the coverage rate of bone graft was 13%-46% (mean, 23.8%). The healing time of bone graft was 3-6 months (mean, 4.7 months). At last follow-up, all bone grafts completely healed without any signs of collapse. There was no graft resorption, ectopic ossification or osteolysis, or obvious aseptic loosening of the acetabular and femoral prostheses. The leg length discrepancy of unilateral hip patients was (2.86±2.18) mm, and the difference was significant when compared with preoperative value (t=17.028, P=0.000). Conclusion For Hartofilakidis type Ⅱ DDH patients, if the lateral acetabular prosthesis not covered by the host bone exceeds 5 mm in primary THA, autologous femoral head can be used for structural bone grafting, and the short- and mid-term effectiveness are favorable.