The antibacterial activity of the aqueous and methanol extracts of sundried leaves of Cassia alata was investigated by testing the extracts against some pathogenic Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa using the Agar cup plate method. The Minimum Inhibitory Concentration (MIC) of the aqueous extract against susceptible test organism was determined using the Agar dilution method. The results showed that the plant part can be used to treat infections caused by S. aureus and B. Subtilis which were susceptible. The in vitro findings justify the use of the extract of Cassia alata in traditional medicine practice for the treatment of some external skin infections. Cassia alata has shown to be a very versatile plant and can be a viable alternative as an antibacterial agent in the future either alone or in combination with other medicinal plants, if formulated into appropriate pharmaceutical dosage forms. Further, scope exists for in vivo research studies with preformulation testing, pharmaceutical dosage formulation and development, pharmacokinetics, safety and efficacy in patients.