Objective To evaluate the effectiveness of free flaps in repairing hot-crush injury in the dorsum of hand. Methods Between February 2003 and February 2012, 32 cases of hot-crush injuries in the dorsum of hand were repaired. There were 25 males and 7 females with an average age of 24 years (range, 16-45 years). The injury causes included machine crush injury in 9 cases, machine-press injury in 13 cases, and iron panel injury in 10 cases. The time from injury to admission ranged from 90 minutes to 8 hours (mean, 3 hours). The wound size ranged from 6 cm × 5 cm to 17 cm × 11 cm. Associated injuries included the extensor tendon necrosis in 12 cases, and the second metacarpal bone necrosis in 1 case. One-stage emergency debridement was performed in all cases; two-stage flap repair was given at 7-21 days when the necrotic area became determined. The dorsalis pedis flaps were used in 9 cases, the anterolateral thigh flaps in 9 cases, the latissimus dorsi flaps in 3 cases, the thoraco-umbilical flaps in 3 cases, and the lower abdominal flaps in 8 cases. The flap size ranged from 7 cm × 5 cm to 18 cm × 16 cm. The donor site was repaired by skin graft or sutured directly. Results All the flaps survived. Primary healing of wound was obtained in 25 cases and delayed healing in 7 cases. Skin graft at donor site survived, with healing of incision by first intention. Twenty-three cases were followed up 6-25 months (mean, 13 months). Thinning was carried out in 8 bulky flaps; the other flaps had good appearance and texture. At last follow-up, the range of motion (ROM) of the metacarpophalangeal joint ranged from 40 to 80° (mean, 58°); ROM of the proximal interphalangeal joint ranged from 35 to 70° (mean, 52°); and ROM of the distal interphalangeal joint ranged from 5 to 25° (mean, 12°). The sensation recovery of the flaps were more than S2. No scar formed at donor site. Conclusion Suitable free flap should be selected to repair hot-crush injury in the dorsum of hand according to size of wound, which will achieve satisfactory results.