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Abstract: Background: Morphology of trochlea affects the patellofemoral stability. Aim of the study was to assess the correlation between trochlear dysplasia and notch index. Materials and methods: Standard MRI sequences on a 1.5 T were used to image the knees of 120 knees (68 males and 52 females) between the age group 8-70 years (Mean age 39.5 years) and were reviewed in the radiology department at St. John’s Medical College Hospital, Bangalore from June 2014 – June 2016. Based on the Dejour classification of trochlear dysplasia, the knees were classified into normalor types A, B, C, and D. A notch index of <0.2 was considered narrow. Normal knees and knees with trochlear dysplasia were compared. Results: 76 of the 120 knees had trochlear dysplasia, of which 50 were Dejour type A, 16 were type B, 9 were type C, and one was type D. Dejour types B, C and D were combined as non-type A. Inter-observer agreement in assessing the notch index was good (Kappa=0.6). The mean notch indices in normal knees and knees with trochlear dysplasia were comparable (0.15 vs. 0.14, p=0.16), as were in Dejour type A and non-type A knees (0.14 vs. 0.15, p=0.44) and in Dejour types A, B, C, and D knees (0.14 vs. 0.15vs 0.15vs. 0.17, p=0.15–0.6). The rate of ACL injuries was similar in patients with normal knees and those with type-A trochlear dysplasia. A low notch index (narrow notch) was not associated with ACL injury. Conclusion: The notch index and trochlear morphology are 2 independent entities and a narrow notch does not necessarily imply a shallow trochlear grove. The identification of a decreased notch width in association with an increased sulcus angle can also contribute to the diagnosis of trochlear dysplasia.