Nigella sativa (NS) is an effective medicinal plant possessing noteworthy antioxidant property. In NS, there are more than hundred phyto-chemicals reported, out of which thymoquinone is the utmost active phyto-constituent having sturdy antioxidative property. Thymoquinone is a cyclicdione, when reacts with sodium azide, converts into α-azido ketones i.e its analogs which are handy with extensive range of reactions. Sodium azide induces stress in plants thereby, modulating the antioxidant system. The present investigation was planned to elucidate the effect of sodium azide at different concentrations (5µM, 10µM, 20µM, 50µM, 100µM and 200µM) on its secondary metabolites (mainly thymoquinone) in NS callus culture extract (NSE). The results showed sodium azide effect on thymoquinone content and a concentration dependent boost in antioxidant property. It was also observed that thymoquinone content and percent yield (analyzed by RP-HPLC; Reverse Phase- High Performance Liquid Chromatography) were minimum (0.033±0.006% and 0.420±0.045%, respectively) at 200 µM sodium azide used. Whereas, antioxidant activity (analyzed by DPPH; 2, 2-diphenyl-1-picrylhydrazyl) was found to be maximum (3.873±0.402%) at same dose. Further, analysis was done for inhibition of oxidative DNA damage at different concentrations of sodium azide on NSE, maximum inhibition of DNA damage (0.243±0.017%) was found at 200 µM concentration of sodium azide. When correlated, strong positive correlation was observed between percent yield and percent thymoquinone, antioxidant property and inhibition of DNA damage. Whereas, strong negative correlation was observed between percent yield and antioxidant property, percent thymoquinone and antioxidant property, percent thymoquinone and inhibition of DNA damage. The findings evidently point out that the content of thymoquinone, antioxidant property and inhibition of DNA damage was affected by sodium azide.