The purpose of this study is estimating and evaluating the value at risk in forex market. For this purpose based on logritme of Euro/Dollar ratio the value at risk were estimated to three methods: Parametric, Historical and Montecarlo, Simulization from 12/10/2004 to 12/3/2009 in time periods 3, 6, 9, 12, 36 months and in confidence level 90, 95, 99 percent. The results of multi-variable tests demonstrated that there is no significant difference in value at risk average based on three methods and the confidence level and multi-time periods on two currency Euro and dollar. The results of back tests demonstrated that validity of calculations for the minimum value at risk is not confirmed but for the maximum value at risk is confirmed.