Stress is unavoidable in everyday life and it can effect on marital relationship. Social support especially from emotionally closed persons as a protective factor can help individuals to deal with stress and buffers the negative effects of life stress on marital satisfaction. In the present cross-sectional study we investigated the relationship between social and spousal support and marital satisfaction in medical staff in Iran. Data collection was performed in 653 medical staff using socio-demographic questions, the ENRICH Marital Satisfaction Inventory, and the Social Support Questionnaire. Women and men did not differ in total social support satisfaction and the total number of supporting people; but, women were more often support providers for their husbands than men were for their wives. Spouse support was a more important indicator of marital satisfaction for women than for men. Also results revealed that spouse support is more important than social support from other resources to explain marital satisfaction. Job satisfaction had an explanatory effect on marital satisfaction especially in men. Furthermore, the findings showed that social support could decrease the explanatory impact of job satisfaction on scales of marital satisfaction. Therefore, focusing on social support, especially spouse support could be an effective approach in family counseling or family education programs to improve marital satisfaction in medical staff.