The aim of the present study was to isolate and study about the antibacterial activity of astaxanthin from Shrimp of the species Metapenaeus dobsoni. Astaxanthin a carotenoid present in marine yeast and crustaceans posses a wide range of pharmacological activity. Shrimp was collected from Cochin, Kerala during the month of August 2012. The samples were collected and transported to the laboratory under iced conditions. The yield of dried shell was determined by weighing after dried at 50°C in oven for 24 h. Samples were stored at two temperatures, of 25°C and -20°C until use. The material was thawed in running water before use and homogenized in a laboratory mixer.The antibacterial activity was studied on several organisms like Bacillus Subtilis, Salmonella typhi, Staphylococcus aureus and Pseudomonas aeroginosa. The extract showed excellent antibacterial activity than the standard chloramphenicol. Among this pseudomonas aeroginasa showed maximum inhibition.