The purpose of this study was to present the clinical significance of rectus abdominis free muscle flap for large sized diabetic ulcer and necrosis of the foot to salvage limb. From June 2000 to February 2006, eleven patients were included in our study. There were seven males and four females with a mean age of 58.3 years (48~65) at the surgery. All had a history of diabetics and subsequent huge soft tissue defect caused by necrotizing abscess formation around the foot and the ankle. After complete debridement of large sized, infected necrotic tissue, susceptible intravenous antibiotics and wound care were done. After control of infection, confirmed by clinical and laboratory findings, the rectus abdominis free muscle flap was applied to cover remained large soft tissue defect and to prevent the recurrence of infection. All flaps survived and it provided satisfactory coverage for the soft tissue defect on the foot and the ankle area for a mean of 41.1 months (24~85) follow up period. All except of one patients did not have any recurrence of infection on the operation site and could salvage their limbs. The rectus abdominis free muscle flap could be recommended for large sized soft tissue defect after necrotizing abscess in diabetic foot to salvage major limb.