Leaf extracts of Bixa orellana Linn. (achuete) using acetone, 95% ethyl alcohol and distilled water as solvents were tested for their antibacterial activity. The acetone and ethanol extracts were effective against the three gram positive test organisms, Bacillus subtilis, Staphylococcus aureus, and Staphylococcus epidermidis. The acetone extract (Bs, 1.27 Sa, 1.33 Se, 1.60) exhibited the greatest antibacterial index compared to the ethanol (Bs, 0.60 Sa, 0.87 Se, 1.27) and distilled water (Bs, 0.40 Sa, 0.60 Se, 0.00) extracts. The distilled water extract showed zones of inhibition against the test organisms S. aureus and B. subtilis. All of the leaf extracts did not show any inhibitory effect against Escherichia coli and Pseudomonas aeruginosa
