Water chestnut (Trapa natans L. var. bispinosa Roxburgh), is an aquatic weed well known for its starchy fruit. The objective of this study is to investigate the fruits of this plant for its medicinal property, viz, activity against Mycobacterium tuberculosis and a non pathogenic species Mycobacterium smegmatis and antioxidant activity. Methanolic and ethanolic extracts of the peel and fruit showed antimycobacterial activity. The ethanolic extract of the peel exhibited the highest antimycobacterial activity with significant MIC values of 12.65 mg/ml and 3.125 mg/ml against M. tuberculosis and M. smegmatis respectively. Total polyphenol (TPC) and contents (TFA) were measured. The ethanolic extract of the peel has been found to contain the highest phenolic and flavonoid contents. The fruit exhibited a total protein content of 6.825 g/100 g. Seven compounds (Phenols and Fatty acid) are detected in the GC-MS study of the ethanolic extract.