Objective To compare clinical effects between percutaneous and open reduction by using tension band wiring for the treatment of transverse patella fractures. Methods A prospective study was carried out. A series of 62 cases of transverse patella fracture from 1997 to 2003 were divided into two groups: the Percutaneous Group (n=27) and the Open Group (n=35). The Percutaneous Group received percutaneous reduction with tension band fixation, including 23 cases of internal fixation by Kirschner-wire techniques and 4 cases of fixation through cannulated cancellous bone screws. The Open Group received open reduction with Kirschner wiring tension band fixation. The time to bone union, the reduction condition, the movement range and the function of the knee were compared between the two groups. Results All the cases were followed for 6~48 months. The bone union was achieved in both of groups. The rate of “good” or “excellent” knee functions was 88.9% in the Percutaneous Group (24/27) and 88.6% in the Open Group (31/35), respectively, without significant difference (?2=0.000,P=1.000). The time to bone union was earlier in the Percutaneous Group than in the Open Group (?2=6.581,P=0.037). Conclusions Percutaneous reduction with tension band fixation can offer good anatomic reduction and enough fixation strength to meet the requirements for bone union and function recovery in the treatment of transverse patella fractures, with minimal invasion, quick union and excellent clinical outcomes.