Plastics have been an integral part of our life. However, disposal of these non-biodegradable (petrochemical derived) plastics poses a threat to our environment. Thus, much interest has been gained in developing biodegradable plastics. Polyhydroxybutyrates (PHBs) are polymers that accumulate as carbon/energy in microbial cells and provide an alternative to petrochemical plastic because of their biodegradability properties. However, major problems in commercializing PHB is the high production cost due to expensive carbon substrates. Therefore, the applications of cheap carbon sources have been explored. In this study, P. aeruginosa has ability to convert agro-industrial waste like Rice husk, Cotton seed husk, Walnut shell and Corn cob meal in to PHB. Highest cellular PHB content was obtained from Rice husk as source of carbon which was found to be 0.26 g/L. As Rice husk is agro-industrial waste its use in PHB production may prove beneficial, and hence may become an area of further research.