Abstract: Introduction: Traumatic knee injuries were conventionally assessed clinically, and subjected to radiographs. In modern Orthopaedics, MRI and a subsequent arthroscopic procedure has come of age. Arthroscopy of the knee is a key hole surgery performed as a daycare procedure. There are many indications however, this study is to correlate the findings subsequent to an MRI diagnosis. Material and methods: 40 patients of different age group and sex with internal derangement of knee (IDK) were subjected to MRI for determining ACL,PCL, medial and lateral meniscus injury.and they were subjected to arthroscopy and the findings were recorded. Results: Magnetic resonance imaging performed on the injured knees revealed 30 tears of the menisci, of which 20 were of medial meniscus and 10 tears of lateral meniscus. There were 21 tears of the cruciate ligaments, out of which 15 were tears of ACL and 6 of PCL. 50 menisci on MRI were normal, of which 20 were medial meniscus and 30 lateral meniscus. Of the 59 cruciates showing normal signal on MRI, 25 were of ACL and 34 of PCL. Arthroscopy revealed 27 tears of menisci, 19 of these were of medial meniscus and 8 of lateral meniscus. 53 menisci were normal on arthroscopy, 21 of medial and 32 of lateral meniscus. There were 19 tears of cruciates, of which 14 were of ACL and 5 of PCL. There were 61 normal cruciates, of which 26 were ACL and 35 were PCL Discussion: The area under the curve of magnetic resonance imaging was 87.6% percent for the medial meniscus, 89.1 percent for the lateral meniscus, 76.1 percent for ACL, and 87.1 percent for PCL in this series of 40 patients. Various intra articular pathologies of the knee such as loose bodies, chondral fractures, degenerative changes, plicae can mimic a meniscal tear. Mucoid and eosinophilic degeneration can cause false positive results on MRI 15. Magnetic resonance imaging is useful as a diagnostic tool in internal derangements of the knee. It is useful in circumstances wh