To evaluate the predictive value of MRI in the early postoperative course after cruciate ligament replacement, a prospective study was performed. Twenty patients with reconstructed anterior and/or posterior cruciate ligament were examined clinically and with contrast-enhanced MRI 2, 12, 24 weeks, 1 and 2 years postoperatively. The clinical examinations were evaluated according to the scores by Lysholm, OAK and IKDC. The MRI scans (SP 63, 1.5 Tesla) were evaluated regarding the quality and signal intensity of the reconstructed ligament. During the first postoperative year a significant increase in signal intensity and inhomogeneity of the neoligament in MRI was observed in 16 patients with an average value for signal/noise of 1.1 2 weeks postoperatively up to 6.9 1 year postoperatively. In 12 patients the reconstructed ligament could not be evaluated in the 1-year postoperative MRI, whereas none of these patients was suspected clinically of having instability. In the 2-year postoperative MRI, the signal intensity of the neoligament was found to be decreasing again with improvement in judgement.