This paper examines the effect of environment risk Tobin Q of accepted companies in Tehran Stock Exchange. This study is applied, regarding the purpose and is casual considering methodology. Statistical population of the study includes all accepted companies in Tehran Stock Exchange from 2008-2012. Using systematic random sampling, sample size of 79 was achieved. To gather data, library method and to test hypotheses, multivariable regression was used. Based on the findings, among 3 (economic, business, and market) variables of environment risk, economic and business risk don’t affect company value; and business risk has a negative effect on company value.
