This paper presents a study to measure the effect of personal characteristics including neuroticism, extraversion, openness to experience, conscientiousness and agreeableness on word of mouth advertisement. The population of this survey includes all people who use mobile phone in city of Tehran, Iran. The study designs a questionnaire in Likert scape and distributes it among 400 randomly selected people who use mobile devices. Using Spearman correlation test, the study confirms the positive of effects of neuroticism, extraversion, openness to experience on word of mouth advertisement and the negative impact of agreeableness on word of mouth advertisement. However, the study does not find any meaningful relationship between conscientiousness and word of mouth advertisement.