Job satisfaction among employees is a crucial issue in an organization and employer plays a vital role to fulfill their needs. Keeping job satisfaction high among workers can be of tremendous benefit to any organization, as happy employees will be more likely to produce work effectively. It has been assumed that personality traits can play an important role in people's dealing with the environmental issues such as work situations. By assuming this effectiveness, the main aim of this essay is to study the relationship between personality traits and job satisfaction. Explaining job satisfaction by using personality traits can enlighten weather job satisfaction depends only on type of organization or on some personality traits. In this regard, present study has investigated the relationship between job satisfaction and personality traits among Iran Khodro Company expert staff. To do so personality characteristics were measured by NEO-PI-R scale and job satisfaction was measured by Job Descriptive Index (JDI scale) that filled by experts of “Iran Khodro” company (111 men and women). Pearson correlation used to analyze the data. Results show that, neuroticism/emotional stability was associated with low job satisfaction (r=−0/713, P<0/01). Also conscientiousness (r=0/620) and agreeableness (r=0/476) was significantly correlated with job satisfaction (P<0/01). But the relationship between extraversion (r=−0/025) and openness to experience (r=0/061) with job satisfaction was not significant. In addition, the results of this study emphasis on the effective role of age (r=−0/301) and job background (r=−0/330) on job satisfaction. But relationship between sexuality (r=0/183) and marriage (r=0/125) with job satisfaction was not significant.