Similarities or differences in personality traits of couples are among the important factors that can predict the stability and marital satisfaction. The present study examined the relationship between couple’s personality similarity and their marital satisfaction in a sample of 100 married couples which have been living together for at least one year. All participants completed a short version of the NEO Five Factor Inventory (NEO-FFI) and a long version of the Enriching and Nurturing Relationship Issues, Communication and Happiness (ENRICH). The results demonstrated that couples similarity in extraversion predicted higher marital satisfaction in women. Couples who both had high scores in neuroticism showed lower marital satisfaction relative to couples who both had low scores in this characteristic. Couples who both had high scores in agreeableness and conscientiousness, showed higher marital satisfaction relative to couples who both had low scores in these characteristics. Based on the results of the present study, similarity in personality characteristics is not the only determinant of marital satisfaction.