Purpose: This study explores the levels of and trends in corporate environmental disclosure (CED) among a sample of Sri Lankan listed companies from 2015 to 2019. Furthermore, this article examines the firm-level determinants of CED, including corporate governance (CG) mechanisms, in Sri Lanka from a multi-theoretical perspective. Design/methodology/approach: Using a sample of 205 firm-year observations, this paper distinctively applies a panel quantile regression (PQR) model to examine the determinants of CED in Sri Lanka. This method was supported by estimating a two-step generalized method of moment (GMM) model to tackle any possible existence of endogeneity concerns. Findings: The authors’ findings indicate an increasing trend in CED practice among the sampled companies (i.e. 41 firms, the only adopters of the GRI framework) in Sri Lanka from 2015 to 2019. However, it is still considered at an early stage compared with other developed counterparts. Furthermore, this study suggests that board size, board independence, board meetings, industry type, profitability and firm size are positively associated with CED level. In contrast, and consistent with our expectation, CEO duality is negatively attributed to the disclosed amount of environmental information in the Sri Lankan context. Research limitations/implications: The authors’ empirical evidence reiterates the crucial need to propagate and promote further substantive CG reforms, mandating CED in Sri Lanka. Originality/value: The authors’ findings provide much-needed insights for indigenous companies, operating across similar emerging economies, to understand how CED can be incorporated into their reporting process based on the GRI framework in order to enhance their firm value, reduce legitimacy gaps and mitigate other operational risks.