High-performance thermoplastic polymers (HPTs) are increasingly used in advanced applications such as aviation or electronics due to their superior chemical and mechanical properties at elevated temperatures. However, producing HPTs is resource- and energy-intensive, resulting in high environmental impacts and production costs. Polyoxazolidinone (POX) has been proposed as a novel HPT with potential environmental and economic benefits compared to reference HPTs by increased process efficiency and readily available inputs. By a combined techno-economic and life-cycle assessment, we show that POX reduces environmental impacts while being cost-competitive compared to reference HPTs polyetherimide, polyethersulfone, and polysulfone. For fossil-based production, POX reduces GHG emissions by 34–45%. Bio-based production combined with renewable energy further reduces GHG emissions of HPTs by 55–78% but leads to environmental trade-offs. The economic evaluation of POX suggests a 26–35% price reduction compared to reference HPTs, and potential markups over 100% in the HPT market. Our results demonstrate how enhanced process efficiency of novel products such as POX can contribute to the decarbonizing polymer industry.