To date, researches have showed that individuals find partners similar to them in different characteristics. Furthermore, partners' similarity may have effects on their relationship satisfaction. The aim of this study was to examine assortative mating in work values, mechanisms through which it develops and to identify effects of assortative mating in work values on relationship satisfaction. The study included 215 couples, aged 19-65 years, who are in relationship more than one year. Participants completed Personal and Organizational Values Scale, Perceived Relationship Quality Components, Satisfaction Index and Marriage Stability Scale. There is positive assortative mating in work values. Partners share similar work values. Partners' similarity reflects influences of initial assortment significantly more than of convergence. Partners are similar at the beginning of the relationship and similarity is not larger in couples who are in a relationship for a long time. Additionally, partners' similarity reflects influences of active assortment significantly more than of social homogamy, which means they actively seek for similar partners and don't choose partners because of the similar social background. Similarity in work values has an effect on relationship satisfaction, but only for women. Women are more satisfied with the relationship when their work values are identical to partner's values or more expressed than theirs. Similarity in work values has an effect on perceived relationship quality, on satisfaction with the partner and on global relationship satisfaction.