This study aims to investigate the nonlinear relationship between environmental, social and governance (ESG) and firm value (FV). The sample includes 38 Taiwan Stock Exchange listed high-tech firms with ESG disclosure between 2005 and 2020.Quantile regression estimation results indicate there is a nonlinear concave-convex ESG-FV relationship, which is also verified by the U-test. Furthermore, there is a different relationship between the individual ESG pillars and FV. The nexus between the environmental and social pillars and FV are concave-convex, whereas the governance pillar has no significant effect on FV. The model in this research offers a valuable analytical framework for exploring sustainability reporting as a driver of performance in the high-tech industry. Overall, we highlight Taiwan's high-tech firms should ensure that both the costs and benefits of the ESG performance for maintaining sustainable development and stakeholder engagement.