Different translators with different personality traits make variant decisions in their translations. In this study, the effect of personality traits of Iranian translators on their performance quality was explored from a psychological perspective. In the first step, the BFI Test (Big Five-Factor Inventory) was administered to the 30 MA translation students in Tehran Islamic Azad University. In the second step, the researcher distributed two different English source texts among the participants for the purpose of translation. Having finished the task of translating, the target texts produced by the students were assessed to investigate the correlation between personality traits and the quality of the translation. Hence, three instructors of translation were recruited to evaluate the translations and correspondingly score them on the basis of Farahzad’s (1992). The analysis of the acquired results proved both of the hypotheses of the study. First, there was a positive relationship between personality traits and translators? performance quality in different text types and also, Psychological model of translators’ personality had a significant effect on assessing the translated works.