<jats:sec> <jats:title>Purpose</jats:title> <jats:p>The manufacturing sector has been a major contributor to annual greenhouse gas emissions in India. Yet, firm-level data on carbon emissions and environmental footprints remain limited, largely because of insufficient corporate reporting. The purpose of this study is to analyze the recently introduced, comprehensive Environmental, Social and Governance (ESG) reports of India’s 100 largest publicly listed manufacturing firms for 2022–2023 to assess their evolving green transition and sustainability efforts, environmental performance and reporting quality.</jats:p> </jats:sec> <jats:sec> <jats:title>Design/methodology/approach</jats:title> <jats:p>Drawing on the mandatory ESG disclosures under India’s Business Responsibility and Sustainability Reporting (BRSR) framework, this study evaluates key parameters reflecting firms’ environmental responsibility, awareness, performance and initiatives. Raw data were collected from the BRSR sections of annual reports of 100 large manufacturing companies, and both quantitative and qualitative data were standardized for analysis.</jats:p> </jats:sec> <jats:sec> <jats:title>Findings</jats:title> <jats:p>The commitment of companies to the green transition is reflected in reductions in greenhouse gas emission intensity, increased use of renewable energy, lower energy consumption and water-use intensity and the widespread adoption of water and waste treatment initiatives. Several firms have set targets for emissions reduction and renewable energy use, while also increasing R&amp;D and capital expenditures related to ESG priorities. Many companies have strengthened their ESG performance and reporting practices, implemented ESG impact assessment initiatives and improved regulatory compliance. Although the uptake of environmental sustainability reporting among large manufacturing firms appears encouraging, significant reporting gaps and risks of greenwashing persist, warranting careful policy attention.</jats:p> </jats:sec> <jats:sec> <jats:title>Research limitations/implications</jats:title> <jats:p>This study indicates that the adoption of the BRSR framework in India has encouraged large manufacturing firms to align with stricter sustainability standards, with important policy implications. The findings of this study provide evidence that disclosure-based regulation can meaningfully accelerate green transition at the firm level. This study is limited to a sample of 100 large manufacturing companies. Accordingly, the findings, conclusions and research implications are primarily applicable to large manufacturing firms and may not be generalizable across other firm sizes or sectors. In addition, the set of environmental indicators analyzed is restricted to those mandated under the BRSR disclosure framework, which is not exhaustive. Finally, this study relies on self-reported information disclosed in annual reports and, therefore, cannot independently verify the accuracy or completeness of reported environmental performance.</jats:p> </jats:sec> <jats:sec> <jats:title>Practical implications</jats:title> <jats:p>The findings of this study provide a set of benchmarks that companies can use to strengthen their decarbonization and sustainability targets, enhance transparency and improve operational practices and initiatives. The results of this study also support disclosure-based policy approaches as an effective driver of corporate green transition and sustainability efforts.</jats:p> </jats:sec> <jats:sec> <jats:title>Social implications</jats:title> <jats:p>This study may help raise public awareness of sustainability through ESG-reporting-driven transparency. BRSR disclosures provide information on corporate practices related to emissions reduction, energy and water conservation, along with a range of key environmental indicators. The findings may contribute to improved environmental health and human well-being.</jats:p> </jats:sec> <jats:sec> <jats:title>Originality/value</jats:title> <jats:p>To the best of the authors’ knowledge, this study is among the first to analyze a range of key firm-level environmental performance indicators for large manufacturing companies, based on their ESG reporting under the latest regulatory norms. This study provides valuable insights into the uptake of corporate environmental reporting practices, as well as persistent reporting gaps.</jats:p> </jats:sec>