Introduction: After multiple-ligament injuries and dislocations of the knee, clinical assessment of the soft tissues is difficult and MRI is generally performed. Hypothesis: MRI is a reliable examination, providing a precise and reproducible assessment of soft-tissue lesions after multiple-ligament injuries or dislocations of the knee. Materials and methods: Forty patients presenting multiple-ligament lesions of the knee were included in this multicenter prospective study. All had an MRI of the knee in the 48. h following their accident. Thirty-four patients were treated surgically. A 17-item standardized interpretation guide was created. Intraobserver reproducibility was assessed by comparing the interpretations of five surgeons at two different times 3 weeks apart. Interobserver reproducibility was evaluated by comparing the results of the interpretations of 40 MRIs performed by three pairs of surgeons. The relevance of the MRI interpretations was determined by comparing the results of the surgeons to those of a radiologist and with the data from the surgical reports. Results: The overall intraobserver and interobserver agreement was low. Comparing the surgeon's results with the radiologist's results and the surgical data, the agreement was low. Discussion: After multiple-ligament injuries and dislocations of the knee, a precise diagnosis is necessary. This study provides an isolated demonstration of the lack of precision and reproducibility of MRI interpretations for the diagnosis of the lesion's topography. MRI should be integrated into a complete assessment with a precise clinical exam and stress X-rays. Level of evidence: Level IV, prospective case-control study.