Polyhydroxyalkanoates (PHAs) belong to a category of polymers that comprise a group of natural biodegradable polyesters which are synthesized by microorganisms. The vital properties of PHAs such as biodegradability, biocompatibility and non-toxicity make them appropriate for applications as biomaterials. PHAs are used in the field of tissue engineering as bone graft substitutes. They are extensively being used for developing new stents for nerve repair, cartilage repair and cardiovascular patches. In implantology, PHAs have been used as sutures and valves. They have also been used as drug carriers for drug delivery systems because the breakdown products are not hazardous for the body due their biodegradability. The mechanical properties of PHAs can be modified by the process of blending to obtain better polymeric properties. This book includes some of the vital pieces of works being conducted across the world with respect to kinetics, bioengineering and industrial aspects of polyhydroxyalkanoates. It will also provide interesting topics for research, which interested readers can take up.