Objective To explore the clinical application of vascular augmentation of an extra-long latissimus dorsi flap through an intercostal artery in limb wound repair. Methods Between January 2016 and December 2017, 5 patients with limb wounds were treated with the extra-long latissimus dorsi flaps. The vascular augmentation of the extra-long latissimus dorsi flap through the intercostal artery was applied during the operation. There were 4 males and 1 female, with an average age of 45.8 years (range, 43-59 years). The time from post-traumatic admission to flap repair was 7-25 days (mean, 12.3 days). The causes of injury included machine injury in 2 cases, traffic accident in 2 cases, and roller crush injury in 1 case. The wounds were located at the anterior of upper limb in 3 cases, the posterior of upper limb in 1 case, and the posterior of leg in 1 case. The size of wounds ranged from 26 cm×8 cm to 38 cm×10 cm. The size of the latissimus dorsi flap ranged from 36 cm×6 cm to 43 cm×7 cm. The size of the muscle flap ranged from 36 cm×10 cm to 43 cm×15 cm. The donor sites were closed directly. Results The distal flap necrosis occurred in 1 case and healed after symptomatically treatment. The other flaps survived completely. The wounds and incisions at donor sites healed by first intention. All patients were followed up 8-18 months with an average of 14.9 months. At last follow-up, the flaps had satisfactory appearances, soft textures, and function of sweating. Conclusion Application of vascular augmentation of the extra-long latissimus dorsi flap through the intercostal artery in repair of limb wound can reduce the incidence of distal flap necrosis and achieve satisfactory effectiveness.