Objective To investigate the effectiveness of the island flap pedicled with the dorsal cutaneous branches of thumb radial digital artery from the same finger for repairing pulp defect. Methods Between June 2009 and March 2010, 10 patients (10 fingers) with pulp defect of thumb were treated. There were 6 males and 4 females, aged 13-68 years with an average of 38 years. Defect was caused by machine crush in 4 cases, by saw machine in 3 cases, by chronic infection in 2 cases, and by burn in 1 case. The disease duration was 3 hours to 4 months. In 4 cases of distal pulp defect (1.0 cm × 0.8 cm to 2.0 cm × 1.4 cm) with exposure of bone or tendon, defect was repaired with island flap pedicled with the interphalangeal joint cutaneous branches of thumb radial digital artery (1.0 cm × 0.8 cm to 2.2 cm× 1.5 cm). In 6 cases of proximal pulp defect (1.0 cm × 0.8 cm to 2.5 cm × 2.0 cm) with exposure of bone or tendon, defect was repaired with island flap pedicled with the metacarpophalangeal joint cutaneous branches of thumb radial digital artery (1.0 cm × 0.8 cm to 2.6 cm × 2.2cm). The donor sites were repaired with skin grafts. Results All flaps and skin grafts survived, and wounds healed by first intention. Ten cases were followed up 6-12months (mean, 8 months). The colour, texture, and contour of the flaps were good. The two-point discrimination was 7-10mm on the island flap at last follow-up. According to total active motion (TAM) standard, the thumb function was assessed as excellent in 8 cases, good in 1 case, and fair in 1 case, and the excellent and good rate was 90%. Conclusion The main digital artery and nerve of thumb will not be sacrified when the island flap pedicled with the dorsal cutaneous branches of thumb radial digital artery is used. The operative procedure is simple, so it is a good method for repairing pulp defect of thumb.