The increasing use of plastics by society and the effects of non-degradable petroleum based plastic wastes on our environment is a growing concern. Polyhydroxyalkanoates (PHAs), macromolecule-polyesters naturally produced by many species of microorganisms, are being considered as a replacement for conventional petroleum-derived plastics. The study described in this book illustrates creation of transgenic plants that produces Polyhydroxybutyrates (PHB), which belongs to PHA family, in developing seeds. Genes responsible for PHB production were isolated from a natural producer, R. eutropha, and introduced into A. thaliana by Agrobacterium-mediated transformation. Homozygous lines with single copy of transgenes were developed and characterised at molecular level. Transgenic seeds were analyzed by Gas Chromatography and found to accumulate 0.772 ± 0.006% PHB (dry weight). This study demonstrates the possibility of biodegradable plastic production in transgenic plants and should be useful to plant science researchers or anyone who may be interested in the subject.