The life cycle assessment (LCA) of PHAs provides information that helps to analyze the environmental impact of this biopolymer. The journey of the PHAs starts with bacteria using various feedstocks such as sewage sludge generated through thermochemical degradation of feedstock and combinations of aerobic and anaerobic digestion. The analysis is an estimate of the energy efficiency of the process, ranging from pyrolysis for producing volatile fatty acids (VFAs) and bacterial cell biomass containing PHA followed by downstream processing (extraction of PHAs with dimethyl carbonate and complete degradation of the biopolymer). The LCA reflects on the energy input and the impact on the environment on a global scale, which includes climate change and depletion of water and resources, along with their impact on processes including acidification, eutrophication, and toxicity. A perusal of fossil fuel and biomaterial-based polymers, including PHAs, reflects that emission of greenhouse gases and energy demand need critical analysis for sustainable PHA production on a large scale.