Although previous research has suggested that interorganizational cooperation and knowledge sharing may affect technological eco-innovation or proactive environmental strategy, there is little understanding of the interconnectedness of these variables. This paper investigates the links between interorganizational cooperation, knowledge sharing, proactive environmental strategy, and technological eco-innovation. In particular, it examines the infl uence of interorganizational cooperation and knowledge sharing on technological eco-innovation and explores these relationships through proactive environmental strategy. A research model has been developed and tested on a sample of 292 fi rms operating in Poland. In order to test the proposed research model and hypotheses, structural equation modeling using partial least squares has been applied. The fi ndings indicate direct effects of interorganizational cooperation and knowledge sharing on proactive environmental strategy. However, the obtained results do not prove that interorganizational cooperation directly affects technological eco-innovation. Nevertheless, the study has shown the signifi cant mediating role of proactive environmental strategy in relationships between interorganizational cooperation, knowledge sharing, and technological eco-innovation. Since proactive environmental strategy powerfully fuels technological eco-innovation and signifi cantly mediates links between interorganizational cooperation, knowledge sharing, and technological eco-innovation, this research proves that it constitutes a unique organizational capability that may improve transformation of knowledge into better environmental and economic performance.