Drawing on the strategic alliances and innovation literature, this study proposes that the impact of technological collaboration on product innovation is contingent on market competition and sectoral technology characteristics. Specifically, it argues that the generally observed positive effect of technological collaboration on product innovation may be diluted in highly competitive markets, and the interactive effect of technological collaboration and market competition on product innovation will be further moderated by sectoral technological intensity. Data on the product innovation and technological collaboration of 944 Chinese firms across five manufacturing sectors provide robust support for the contingent effects of technological collaboration on product innovation.