Abstract: Objective To explore the effects of pedicled anterolateral thigh flaps in repairing skin and soft tissue defects in perineal region caused by necrotizing fasciitis. Methods From March 2014 to December 2018, 6 patients with skin and soft tissue defects in perineal region caused by necrotizing fasciitis were admitted to Department of Burns of Hanzhong Central Hospital (hereinafter referred to as our hospital). Two female patients had labia major defects and 4 male patients had scrotum defects, with age of 43-68 years. The areas of skin and soft tissue defects after debridement were 4%-8% total body surface area. The wounds in non-joint and non-functional area were repaired with free split-thickness skin grafts from medial femoral region, and the residual wounds areas in perineal region after repair were 10 cm×4 cm-22 cm×10 cm, which were repaired with pedicled anterolateral thigh flaps, with area of 12 cm×5 cm-24 cm×12 cm. The secondary wounds in the donor sites were sutured directly or repaired with free split-thickness skin grafts from medial thigh on the same or opposite side of the wounds. The bacterial culture result of wound exudate, drug sensitivity test result, and blood bacterial culture result on admission were recorded. The postoperative flap survival was observed. The length of hospital stay, debridement times, and antibiotics use time were recorded. The flap swelling condition was observed to evaluate whether flap thinning operation was necessary, the sensory recovery of the flap and hip joint activity were evaluated, and the scrotum function of male patients was evaluated by urologist in our hospital during follow-up. Results The bacterial culture results of wound exudate in 5 patients on admission showed Escherichia coli with 4 of them having the same bacteria and the other one having methicillin-resistant Staphylococcus aureus detected in their blood samples. All the flaps survived in 6 patients after the operation, with total length of hospital stay of (22±5) d, debridement of 3-5 times, and antibiotics use time of (13±3) d. During follow-up of 3 to 6 months after the operation, the flaps were slightly bloated in 2 patients, and the flap thinning operation was performed 6 months after wound repair. The sensory function recovered to normal in 2 flaps of patients with anterolateral femoral cutaneous nerve, and the superficial sensory function in the other flaps of patients recovered in different degrees.The hip joint activity was close to normal in all the patients, and the scrotum function was normal in 4 male patients. Conclusions The pedicled anterolateral thigh flap showed good effects in repairing skin and soft tissue defects on perineal region caused by necrotizing fasciitis, with good appearance and function after operation, and the method is simple, safe, and easy to apply.