This study aims to analyze the influence of profitability, firm size, and financial leverage on the practice of income smoothing in manufacturing companies listed on the Indonesia Stock Exchange (IDX) during the period 2020–2024 from the perspective of Islamic financial management. The background of this research is based on the importance of financial statement quality in investment decision-making, as well as the phenomenon of income smoothing practices that continue to attract attention from academics and practitioners. The research method employs a quantitative approach with a descriptive research design. The population includes all manufacturing companies listed on the IDX, with a sample of 21 companies selected through purposive sampling. Secondary data in the form of financial statements were analyzed using multiple linear regression with the assistance of SPSS 24 software. The results indicate that profitability has a positive and significant effect on income smoothing, while firm size has a significant negative effect. Meanwhile, financial leverage does not have a significant effect on income smoothing. Simultaneously, profitability, firm size, and financial leverage significantly influence income smoothing. These findings suggest that internal company factors are important determinants in the practice of earnings management. From the perspective of Islamic financial management, income smoothing needs to be carefully examined to ensure alignment with the principles of transparency, accountability, and fairness. Thus, this study contributes to understanding the dynamics of financial factors affecting income smoothing and their implications for investors and company management.