Tax has long been collected as the most important source of government revenue. On the other hand, the companies have always been trying to pay less tax. Tax avoidance is one of the approaches taxpayers can use to reduce the amount of tax. This study intends to investigate and identify the factors affecting tax avoidance. Disclosure quality, financial constraints, conservation, managerial overconfidence, auditor expertise, product market competition and corporate governance are independent variables and tax avoidance is dependent variable. To evaluate the impact of tax avoidance, the variable was regarded as independent variable and return on assets, return on equity, economic value added, the value of the company and operating cash flow were dependent variables. For this purpose, the data of 103 companies were analyzed using the software SmartPLS3 and partial least square method in 2011-2015. The results showed that disclosure quality, managerial overconfidence, auditor expertise, financial constraints and firm size had a positive significant effect on tax avoidance. On the other hand, no relationship was observed between product market competition, corporate governance and conservation and tax avoidance. The results also indicated that tax avoidance had no significant effect on return on assets and economic value added, but a positive significant effect on return on equity, value of the company and operating cash flow.