Lipids were extracted from the liver of Bennett’s Sting Ray and muscle of Silver Ribbon fish by solvent extraction method and then purified by suitable conventional method. Various physical and chemical characteristics of the lipid samples have been determined and compared with those of standard fats or oils. Fatty acid compositions of the samples were investigated by Thin Layer Chromatographic (T. L. C.) examination. The liver lipid of Bennett’s Sting Ray was found to have Palmitic acid, Stearic acid and Oleic acid while the muscle lipid of Silver Ribbon fish was found to contain Palmitic acid, Mysteric acid, Linolenic acid and Erucic acid respectively with some other unknown fatty acids. Antimicrobial activities (antibacterial activity against ten human-pathogenic bacteria and antifungal activity against four phyto-pathogenic fungi) of the lipids were tested by standard method.The lipid containing liver of Bennett’s Sting Ray and muscle of Silver Ribbon fish were analyzed quantitatively for the determination of percentages of protein and mineral (N, P, K, Ca) contents by modified Kjeldahl method.