The purpose of this descriptive-internet survey was to examine whether Persian- English bilinguals express different personality traits when they switch language when responding to Big Five Inventory (BFI) as a measure of personality once in Persian and once in English. It has been proposed that language activates cultural specific frames and bilinguals represent different personality patterns in each language. In this research 60 Persian- English sequential bilinguals living in the United States were selected by volunteer sampling method. They were asked to respond to an online version of BFI in both languages. The result demonstrated that, bilinguals had higher levels of Agreeableness, Extraversion, and Openness in English than in Persian where as their scores for Neuroticism were lower in English. These findings support the effect of language on personality and demonstrate the function of language as a strong cue for Cultural Frame Switching (CFS) since language was able to activate CFS for Agreeableness, Extraversion, Openness, and Neuroticism.