The present study reports the production of polyhydroxyalkanoates (PHA) from marine bacteria. During the course of our microbial prospecting, bacterial strain E3 isolated from the sediment sample collected from Vellar estuarine region was found to produce PHA. Optimization of PHA production from the strain E3 was carriedout by classical one factor at a time method. In optimization studies, glucose, ammonium sulphate and sesame oil cake was found to influence the PHA production. There is no significant effect was observed on PHA production when the medium supplemented with various concentration of trace salt solutions. The potential strain E3 was characterized and identified as Carnobacterium sp (E3). This marine bacterium is a newly added source for PHA production.