Aims and Objectives: The aim of this study was to establish normal measurements of the optic nerve sheath diameter (ONSD) on magnetic resonance imaging (MRI). Materials and Method: 100 normal individuals between 3 months and 79 years were included in this study and diameter of ONS was taken at 3 mm behind the globe in T2W sequence using 1.5 tesla Magnetom Essenza Siemens MRI machine and the result was analysed. Results: A total of 100 participants with mean age of 31.11 years were studied. The overall intraorbital mean ONSD was 4.656 mm (range: 3.6 mm–7.6 mm, (S.D.- 0.732) on Rt side; while on Lt side it was 4.663 mm (range: 3.3 mm–7.6 mm, (S.D.- 0.733). There were no statistical differences in the measurements between gender and also laterality. Our range were consistent with many published data on ONSD. Conclusion: There are few studies done in Indian population to measure normal ONSD. So, this study can be used as reference in the management of conditions affecting ONSD.