Objective To evaluate the primary cl inical effectiveness of Austin metatarsal osteotomy combined with transection of adductor muscle and transverse metatarsal l igament for treating mild or moderate hallux valgus through a single medial incision. Methods Between May 2006 and January 2009, 41 patients (45 feet) with mild or moderate hallux valgus were treated. There were 9 males (10 feet) and 32 females (35 feet) with an average age of 45.3 years (range, 23-71 years). The hallux valgus angle (HVA) was (33.1 ± 1.4)°, and the first and second inter-metatarsal angle was (20.4 ±1.1)°. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score of the affected foot’s function was 47.2 ± 3.7. A longitudinal medial incision was made at the first metatarsophalangeal joint. By the incision, Austin metatarsal osteotomy and lateral soft tissue release (including transection of adductor muscle and the transverse metatarsal l igament) were performed at the same time. Results During operation, 1 case had superficial peroneal nerve branch injury and suture repair was done microsurgically. All incisions healed by first intention postoperatively. All patients were followed up 16-36 months (mean, 26 months). Medial forefoot numbness occurred in 2 feet at 3 days after operation and rel ieved within 6 weeks. The X-ray films showed bone heal ing at osteotomy site within 8 weeks after operation. At last follow-up, the HVA was (10.7 ± 1.7)°, showing significant difference when compared with preoperative value (t=22.32, P=0.00), and the first and second inter-metatarsal angle was (12.1 ± 1.7)°, also showing significant difference when compared with preoperative value (t=21.17, P=0.03). The postoperative AOFAS ankle and hindfoot score of the affected foot’s function was 84.9 ± 4.5, showing significant difference when compared with preoperative score (t=20.75, P=0.01). No foot hallux varus, hallux valgus, or metatarsal necrosis occurred during follow-up. Conclusion The Austin metatarsal osteotomy combined with transection of adductor muscle, transverse metatarsal l igament through a single medial incision can effectively correct the mild or moderate hallux valgus, and avoid the scar and injury of deep peroneal nerve branches by traditional lateral incision.