Objectives: To develop and evaluate the validity and reliability coefficients of Iranian Adolescents Risk-taking Scale (IARS) and its subscales was the aim of the current study. Method: After reviewing the proposed instruments in this field, and with considering the cultural features and circumstances of the Iranian society, the Iranian Adolescents Risk-taking Scale (IARS) was developed in 38 items. 1204 students were selected from Tehran high schools using multistage sampling, and all subjects completed IARS. Data were analyzed using exploratory factor analysis and goodness of fit index. Results: Exploratory factor analysis indicated that IARS is a 7 dimensional scale, which explains 64.84% of the overall risk variance. The Cronbach’s alpha for the total scale and subscales were 0.94 and 0.74-0.93 respectively. Conclusion: The psychometric properties of IARS are consistent with the cultural indices of Iranian society.