The purpose of this research is to investigate the impact of conditional and unconditional conservatism on distress risk of the companies listed in Tehran Stock Exchange. To quantify the conditional conservatism, the ratio of accumulated non-operating accruals to accumulated total assets and the ratio of net income before extraordinary items to market value of equity were used. For measuring unconditional conservatism, the ratio of total accruals before depreciation to average total assets and the ratio of the book value of common shareholder's equity to equity market value were applied. Distress risk is measured by Altman’s Z'-score and Ohlson's O-Score.
In order to achieve the research objectives, two main hypotheses and eight sub-hypotheses have been developed. To test the hypothesis posed in this study, the State software version 9.1 and Eviews version 7 were used. To test the main hypothesis two major general regression models are estimated. Statistical sample is composed of 127 firms between 2000-2009. The result shows that conditional and unconditional accounting conservatism can reduce Iranian company’s distress risk. But this relation is not statistically significant. Therefore, faster recognition of bad news relative to good news (conditional conservatism) and the use of procedures that are inherently conservative (unconditional conservatism) have not created significant and measureable changes in companies’ distress risk.