Background: In particular during extension, the posterolateral corner of the knee (PLC) acts as a substantial rotational and transitional stress resistor. The interplay of numerous overlapping structures creates the multi-compartment complicated sector known as the posterolateral corner. Objective: Assessment of conventional MRI role in posterolateral corner of the knee. Patients and Methods: The study was a cross-sectional study. It was conducted at the Radiodiagnosis Department, Zagazig University Hospitals during six months. It included 36 symptomatic patients with knee trauma before the MR examination. Their ages ranged from 21 to 53 years. Results: According to LCL pathology among the studied cases there were 16.7% intact, 33.3% with sprain, 25% with partial tear and 25% with compete tear. According to PT pathology there were 19.4% intact, 66.7% with sprain, 5.6% with partial tear and 8.3% with compete tear. According to BF pathology there were 94.4% intact and 5.6% with compete tear. According to ITB pathology; 94.4% intact and 5.6% with ITB friction syndrome. According to PFL pathology, 50% intact, 25% with sprain, 16.7% with partial tear and 3 (8.3%) with compete tear. There was remarkable variation between patients and healthy persons in LCL, PT, BF, ITB, and PFL lesions. Conclusion:We came to the conclusion that MRI offers a superb, in-depth assessment of the knee's posterolateral corner structures and lesions. Chronic posterolateral instability can be caused by an unsuspected posterolateral corner injury. To improve surgical care, suggestive imaging results should be quickly communicated with the orthopedic surgeon.