Orientation: The emergence and adoption of integrated reporting (IR) opens up a new agenda for improving the level of environmental disclosures, especially for listed companies. This study explores the environmental information disclosed by mining firms that are listed on the Johannesburg Stock Exchange (JSE) and in essence expects that the level of corporate environmental disclosure (CED) will improve compared to the periods prior to the mandatory requirement of IR. Research purpose: This article examines the extent to which IR has influenced the level of CED among mining firms listed on the JSE. In addition, it determines variation in the level of CED on account of corporate governance attributes and firm-based characteristics. Motivation for the study: The natural capital is an integral fundamental concept upon which the other five capitals depend. The negative impacts of mining activities on the environment necessitate that mining firms demonstrate higher levels of commitment in this regard. Research approach/design and method: This study utilises data for the top 100 mining firms in the JSE between 2015 and 2018. This study obtained data on environmental and other variables through content analysis of the annual integrated and sustainability reports of sampled mining firms. Data analysis involves descriptive statistics and a one-way analysis of variance (ANOVA), with the aid of the Statistical Package for Social Sciences version 21. Main findings: We found no improvement in the level of CED under the IR approach compared to earlier periods. Further, the study found that firm size and board size are associated with the level of CED. Practical/managerial implications: If greater disclosure of information is preferable to less, policy-makers and regulators should give particular attention to environmental issues by extending the minimum regulatory requirements concerning the concept of the natural capital. Contribution/value-add: This study is one of the first few studies that bring to fore the relevance of IR to CED in the South African mining sector.