The clinical importance of primary cruciate ligament reconstruction without augmentation-plasty is discussed on the background of long term results following 51 operations. Based on standardized methods of evaluation 38 patients had a very good and good result, in eleven cases the operation lead to a fair and in two cases to a poor result. A significant instability with a pivot shift grade III was recorded in two cases: twelve patients showed a low degree of instability whereas 37 patients had regained full stability. The coincidence of a cruciate ligament lesion and a rupture of a collateral ligament had a negative influence on the postoperative long term result (p less than 0.01). Our results suggest that a primary repair without augmentation-plasty is a qualified procedure for stabilizing the knee joint in cases with an acute femoral rupture without accompanying collateral lesions. In patients with old ruptures or a complex joint lesion primary repair with augmentation is recommended.