Abstract: Ultra Violet (UV) radiation is capable of producing oxygen induced damage in bacteria. Standardization of Salmonell typhi bacteria strain was done and the free radical scavengering effect of gymnema leaf extract was determined on UV light induced free radicals. Total flavonoid, total phenolic and total tannin content of gymnema leaf extract was also determined. Extract of gymnema leaf significantly inhibited UV induced damage in Salmonella typhimurium. In gymnema leaf extract total flavonoid was found to be 0.2574 mg g-1 expressed as rutin, total phenolic was found to be 15.16 mg g-1 expressed as gallic acid and total tannin content was found to be 2.0785% expressed as tannic acid. The protection of Salmonell typhi may be due to the presence of acidic compounds, flavonoids, saponins, tannins (phenolic compounds) and triterpenoids found in the preliminary photochemical screening.