Anterior cruciate ligament (ACL) is considered as an intra-capsular extra-synovial ligament, primarily responsible for resisting anterior displacement of the tibia on flexion and extension. Magnetic resonance imagining (MRI) has been applied to musculoskeletal patho-anatomy and has been shown to be an effective tool for definition and characterization of knee pathology, regarding the knees subjected to MRI examination, measurement was done for length from femoral to tibial attachment site and thickness at the mid-portion. Comparison between the data obtained in the present study with data obtained from Kowen results there is variable length and thickness. Concluded that for the anterior cruciate ligament the length and thickness of the native ACL played an important role for choosing the type of graft and for the preparation of the graft and dimensions of the native ACL have to be considered in graft selection for anatomic ACL reconstruction.