Abstract: This study was carried out to determine the phytochemical composition and antibacterial effect of Tamarindus indica on E. coli, S. aureus and P. mirabilis. The plant materials of Tamarindus indica stem bark and leaves were obtained from Ahmadu Bello University, Zaria Kaduna State. One hundred (100g) of the plant powder each, was extracted with methanol and chloroform by Soxhlet extraction method. All the extracts were subjected to standard phytochemical screening for the presence or absence of various secondary metabolites. The susceptibility test of the plant extracts on E. coli,S. aureus and P. mirabilis were done using agar well diffusion method. Ciprofloxacin (10 µg) was used as positive control. The phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, tannins, saponins, cardiac glycoside, steroids and carbohydrates. The antibacterial activity of stem and leaves showed that, the plant extract was effective in all the bacterial isolates, and the activity increased with increase in concentration of the plant extracts. Highest activity was showed by leaves methanol extract (LME) at 100mg/ml with zone of 16mm, and it has higher activity than ciprofloxacin which is the positive control with zone of 15mm.