Abstract: Objective To study the efficacy of intravenous urokinase administrationin preventing and treating vascular crisis in limb or finger replantation (LFR). Methods From September, 1999 to October, 2003, 158 patients underwent RSLF in whom 600 000 U of urokinase diluted in 30 ml saline was injected intravenously after blood vessel suture. An intermittent dose (200 000 U) per 12 h given postoperatively for maintenance. A large dose of 1 000 000-1 500 000 U of urokinase was used in the event of vascular crisis. The D-dimer, fibrinogen, hematin, and blood platelet were measured in these patients before and after urokinase administration. Results Vascular crisis was not observed in 117 patients (74.1%) undergoing LFR, and in the 41 patients who developed vascular crisis, relief was achieved by high-dose urokinase (90.2%) with failure occurring in only 4 cases (one with wrist and 3 with finger replantation) for whom re-operation was required. The result was better than those in relevant reports. Conclusion A moderate dose of urokinase can be used after suturing the vessels and intermittent small doses prove feasible postoperatively to prevent thrombosis in RSLF. A high dose of urokinase can be safely used for vascular crisis management in the early stage.