The study was designed for phytochemical investigations of ethanolic extract of bark and leaf of Swietenia mahagoni belonging to the family of Meliaceae and evaluation of their biological activities with the special emphasis on analgesic, anti-inflammatory, anti-microbial and cytotoxic screening in different animal model. Phytochemical investigations were done by extensive analysis with high resolution proton NMR spectroscopic data. The ethanol extract of stem bark was partitioned between pet-ether, dichloromethane and methanol fractions. Chromatographic isolation of dichloromethane fraction using column chromatography followed by preparative TLC afforded tetranortriterpenoid compound. Ethanol extract and different fractions showed significant analgesic and anti-inflammatory potential.From the bio-assay of different fractions and extract, significant cytotoxic properties were evaluated whereas mild to moderate antimicrobial activity was found in this study.