This paper explores the effects of men's attitudes and beliefs on their use of family planning methods in Iran. In particular, two hypotheses are offered and tested. The family planning responsibility hypothesis asserts that men's belief that family planning is the responsibility of women reduces the likelihood of their participation in family planning activities. The community norm hypothesis asserts that men's belief that community approves their participation in family planning activities increases their participation. Data is gathered in 1997 from a province in southern Iran. Multivariate statistical methods are used in order to analyze the data and test the research hypotheses. The results of analysis confirm both hypotheses and also show that communication between spouses increases the probability of using family planning methods by men.