This study investigated the phytochemical, antimicrobial and antioxidant properties of methanolic leaf fractionated extracts of Excoecaria agallocha. Antibacterial activity test of fractionated extract of Excoecaria agallocha was conducted via Disk diffusion assay. Micro titer broth dilution technique was performed to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC). Qualitative and quantitative DPPH radical scavenging activity determines the antioxidant activity in E. agallocha. Chromatographic separation was completed using thin layer chromatography (TLC) and column chromatographic techniques. Phytochemical screening of fractionated extract revealed active constituents including alkaloids, saponins, flavonoids, terpenoid and tannins. In vitro antibacterial activity of columnfractionated extract demonstrated inhibitory effect against Flavobacterium indicum, Chryseobacterium meningosepticum, Chryseobacterium indologenes and Chryseobacterium gleum isolated from diseased fish. MIC and MBC of E. agallocha fractionated extract was 1.56 mg/ml and 3.12 mg/ml, respectively. TLC-based qualitative DPPH analysis revealed antioxidant activity in E. agallocha extract, specified by yellowish stain on maroon color TLC plate. These bands indicate the presence of various compounds that could act as potential antimicrobial agents. The present study indicates that E. agallocha leaves contain active phytochemicals which inhibit bacteria and could be useful in the treatment of microbial infections in fish.