Objective: Early maladaptive schemas are deep feelings or patterns that are formed in childhood and recur later in their lifetime. Young has classified these schemas. The purpose of the present study was to validate the Young Early Maladaptive Schema Questionnaire (YEMSQ) for early maladaptive schemas in a group of university students.Methods: Five hundred and seventy nine students were randomly selected from the freshman students of 2009 semesters. The participants completed the YEMSQ and Criterion questionnaires. Then data was analyzed by Factor analysis of Varimax Rotation sort. Factor analysis by principle components analysis (Varimax Rotation) revealed eighteen factors (that account for a high level of the variance).Results: Data were indicative of high level of Coranbach, Alpha and Split-half (86% and 91%) reliability coefficients of the YEMSQ and the extracted factors. The convergent and discriminate validity of the questionnaire was examined by some measurement tools for psychological distress, positive and negative affect, self- confidence, cognitive vulnerability for depression and personality disorder. The correlation results for the six criteria are sequentially as follow: 37%, 34%, 40%, 39%, 35%, and 36% which were significant at p<0001. There were no significant differences between male and female (except for the factors 7, 12, and 14) and age groups with respect to early maladaptive schema degree.Conclusion: The results of factor analysis are consistent with previous findings showing that YEMSQ can be used in research and clinical settings and in screening the normal among early maladaptive schema population in Iran.