Effect of family control and internal auditor on conservatism behaviour

In this study, we deal with the effect of internal auditor and family control on operational accrual items measurements across the Tehran Stock Exchange registered firms. The operational accrual items of the Giuli and Hin Model have been used to measure the conservatism level. In comparison with other models, including Basu’s model, the above-mentioned model is more reliable. "Herfindal-Hirschman Model” has been used to measure the family control. A total of 125 corporations were selected randomly in 2009 - 2011 for this study. Both regression and Pearson methods were used as the statistical methods of the study. Our findings approved the very intensive relationship between the internal auditor and the operational accrual measurement item. The impact of the family control over corporations on their conservatism level has been verified, as well; there was a positive and direct relation between the two mentioned variables. Also, the effects of firm size and financial leverage on the operational accrual items have been approved; the relation between these variables was more intense. Key words: Conservatism, family control, internal auditor.