Cassava (Manihot esculenta) is a tropical perennial plant and starchy root of cassava is the majour source of carbohydrates for approximately 800 million people in developing regions of the tropics. Although cassava production has increased drastically in last decade in Sri Lanka still there are no significant studies have been conducted to analyse the proximate compositions of recommended cassava varieties in Sri Lanka. The purpose of the current study was to analyse the proximate in the flesh and peel of the Cassava variety “MU-51”. The root peel had significantly high amount (p<0.05) of moisture (70.80±0.09), fat (0.42±0.06) and fibre(1.74±0.03) content than the flesh. The root flesh contain high amount of ash(1.26±0.04) and protein(1.13±0.19) than the peel even though the difference was not significant (P>0.05). There was significant negative correlationship(p<0.05) exist in between Moisture flesh versus carbohydrate flesh and moisture peel versus protein flesh, fat flesh versus protein flesh and significantly possitive correlationship (p<0.05) exist among moisture peel versus fat flesh.