This study aims to examine the effect of the tax ratio, profit margin, capital structure, and state-owned enterprise (SOE) ownership status on greenwashing practices, as well as the moderating role of ESG report assurance. A quantitative approach was employed using secondary data obtained from the annual reports, sustainability reports, and financial statements of Basic Materials sector companies listed on the Indonesia Stock Exchange during the 2022–2025 period. The sample consisted of 55 companies with 220 firm-year observations selected through purposive sampling. Data were analyzed using panel data regression with the Random Effect Model (REM) and White period cross-section cluster standard errors to produce robust estimates against heteroskedasticity and autocorrelation. The findings reveal that profit margin has a negative and significant effect on greenwashing, indicating that more profitable companies are less likely to engage in misleading environmental reporting. SOE ownership status also shows a negative effect on greenwashing at the 10% significance level, whereas the tax ratio and capital structure have no significant influence. Furthermore, ESG report assurance strengthens the negative relationship between profit margin and greenwashing at the 10% significance level but does not moderate the relationships between the tax ratio, capital structure, or SOE ownership status and greenwashing. These findings suggest that the effectiveness of ESG report assurance in enhancing the credibility of sustainability reporting depends largely on firms’ internal characteristics, particularly profitability. The study provides practical implications for companies, investors, regulators, and other stakeholders in improving sustainability reporting transparency and reducing greenwashing practices.