Oil extracted from Swietenia mahagoni seed was studied with a view to finding out its suitability for ethnomedical use with special focus on antimicrobial and toxic behavior. Some of its physical and chemical properties were examined and compared with those of standard oils: olive, sunflower, cotton seed, Linseed, soybean, coconut, palm and castor. The refined oil was found to show good to moderate activity against disease causing bacteria viz. Shigella dysenterial, Salmonella typhi, Staphylococcus aureus and fungal pathogens viz. Macrophomina phascolma, Alternaria alternate Curvularia lunata. Different extracts from Swietenia mahagoni seed showed minimal toxic effect while applied on predatory fish's viz. Heteropneustes fossils and Anabas testudineus.