This study aims to analyze the influence of green accounting, environmental performance, and company size on the financial performance of coal-based energy companies listed on the Indonesian Sharia Stock Index (ISSI) for the 2021–2024 period. The study employed a quantitative approach with a causal associative approach. Secondary data were obtained from annual reports, sustainability reports, company financial reports, and data from the Corporate Performance Rating Program in Environmental Management (PROPER). The sampling technique used purposive sampling based on specific criteria. Financial performance was proxied using Return on Assets (ROA), green accounting was measured using the GRI 300 disclosure index, environmental performance was measured using the PROPER rating, and company size was measured by the natural logarithm of total assets. Data analysis was performed using multiple linear regression. The results showed that green accounting had a positive effect on financial performance. Environmental performance also had a positive effect on financial performance, indicating that companies with better environmental management tended to have higher levels of profitability. Furthermore, company size had a positive effect on financial performance because companies with larger assets have a better ability to manage resources and generate profits. Simultaneously, green accounting, environmental performance, and company size significantly influence the financial performance of coal-based energy companies listed on the ISSI (Indonesian Standard Chartered Accountants). This finding underscores the importance of implementing sustainable business practices to improve financial performance and support long-term corporate sustainability.