Introduction: Income distribution is one of the most important concerns of governments. Thus, governments try to reduce income inequality in society. However, to tackle this issue, the main factors affecting income distribution should be studied.

  Method: In this paper, thus, the most influential macroeconomic variables on income distribution in Iran are examined. Using time series data of 1971-2007 and employing Auto Regressive Distributed Lag (ARDL), the main income distribution factors are reviewed and analyzed.

  Findings: The results have revealed that dynamic approach moves toward a long term model and the outcomes of the long term model show that an increase in the growth rate of real per capita GNP and in the share of agricultural value added in GNP will lead to a reduction in income inequality.

  Conclusion: However, increase in population growth rate and some events such as 1979 revolution and 8 year Iraq-Iran war have increased income inequality in Iran.