The present study was conducted to determine the antibacterial activity of Tribulus terrestris against Bacillus which is a potent pathogen whose various species are responsible for causing a number of diseases. Two extracts, namely water and ethanol extracts of Tribulus terrestris were screened for antibacterial activity by disc diffusion method, in which filter paper discs of various concentrations of the extract were prepared and used. It was observed that, at a concentration of 30mg/ml both water and ethanol extracts were more effective as they gave larger inhibition zones at this concentration then the other concentrations of 15, 20, 25mg/ml. The present study also showed that the ethanol extract of Tribulus terrestris was more effective then the water extract. So, it was concluded that Tribulus terrestris is an effective medicinal plant which show effective antibacterial activity against Bacillus a potential pathogen.