Taxation in public law, in addition to providing government revenue, serves as an instrument for income redistribution, the realization of social justice, and poverty reduction. This study examines the relationship between the tax system and poverty in Iran using a descriptive-analytical method and drawing on legal sources, legislative documents, and economic studies. The findings indicate that the effects of taxation on poverty are not unidirectional and that tax revenues alone are not an adequate criterion for assessing the social performance of the tax system. Significant reliance on indirect taxes, weak taxation of certain forms of wealth and capital gains, tax evasion, informal economic activities, and limited transparency may result in an uneven distribution of the tax burden and increase pressure on the formal sectors of the economy. Conversely, exemptions for certain essential goods and services, support for low-income groups, bread and energy subsidies, the expansion of basic health insurance, and developments concerning taxation of speculative activities demonstrate the supportive capacities of the public finance system. Therefore, the impact of taxation on poverty depends on the coordination of tax policy with social support policies, the subsidy system, and public expenditure allocation. Reforming the tax system requires strengthening direct taxes based on ability to pay, improving the identification of income and wealth, reducing tax evasion, reviewing tax exemptions, mitigating the adverse effects of indirect taxes, and establishing a transparent link between tax revenues and government social expenditures.