Polyhydroxyalkanoates (PHAs) are a class of biodegradable, biopolymers with a potential to substitute fossilbased polymers in diverse applications. However, the ecological competitiveness of PHAs with fossil polymers is still in question. PHAs production from industrial residues based on biorefinery concepts provide a promising production strategy for PHAs to become more ecologically as well as financially competitive with their fossilbased counterparts. This thesis investigates the ecological performance of PHA production from three different types of industrial residues; animal slaughtering waste, industrial surplus whey and waste water from food industry in two different energy provision scenarios. Ecological foot printing by the sustainable process index (SPI) was employed for the evaluation. The ecological “hot spots” In addition, the ecological footprints of PHAs were compared to those of fossilbased polymers. In terms of SPI values, all PHAproduction alternatives, in both energy scenarios were lower than those of the fossilbased polymers, with the exception of PHA production from waste water. The same results apply to carbon dioxide emissions. Conversely, fossilbased polymers were mostly more competitive with respect to global warming potential (GWP) impact category.