Background: MRI has high sensitivity and specificity regarding the assessment of the post-operative knee joint. Purpose: to assess the role of MRI in evaluation of the post-operative knee joint and assessment of the post complications after ACL, meniscal and cartilage surgical repair procedures. Patients and Methods: this study included 20 patients, their age range between 14-50 years, all presented postoperative knee were referred to Radiology Department at El-Hussien University Hospital and private centers for MRI exam for post-operative assessment, complication or follow up after orthopedic examination from Orthopedic Department at El-Hussien Hospitals and Outpatient Clinic. Patients had MRI imaging of the affected knee joint using high field strength scanners (1.5 T) MRI unit (Achieva, Philips medical system) MRI was performed by Knee coil in all cases. Results: this study included 15(75%) males and 5 females (5%)(A) Due to different types of operations 10(50%) had ACL reconstruction,6(30%) had menisectomy,4(20%) had cartilage repair. (B) Due to causes16(80%) trumatic,4(20%)non trumatic. (C) Due to types of complications: 3(15%) had no complications,12(60%)had swelling, 2(10%) had limitation of movement,2(10%) had pain and limitation,1(5%)had pain and swelling. Conclusion: MRI proved as an accurate method for evaluation of the knee joint after ACL, meniscus and cartilage repair that can help predict post-operative complications.