The current study was to investigate the hidden antibacterial potential of Thespesia populnea (L.) Sol. ex Corr. (Malvaceae) against some selected bacterial pathogenic strains responsible for diarrhoea and dysentery. The research work was done in the laboratory of P.G. Department of Botany, Utkal University, Odisha during the month of November 2012. Five bacterial strains were used in the study i.e. Escherichia coli (MTCC-614), Shigella flexneri (MTCC 9543), Staphylococcus aureus (MTCC-1430), Salmonella paratyphi (MTCC-3220) and Salmonella enterica typhi (MTCC-733). The study revealed that n-Hexane extract of Thespesia populnea exhibited the highest zone of inhibition against S. aureus at 6mg/ml and quite comparable with reference antibiotic Ciprofloxacin (0.5 mg/ml).The methanol extract was moderately effective against all above bacteria. From the phytochemical analysis it was found that the plant contained tannin, alkaloid, flavonoid and triterpenoid. The result indicated that the bark extracts of Thespesia populnea might be a source for a new drug against diarrhoea and dysentery which needs further investigation.