This prospective study uses qualitative methods to examine the social and economic impact of family planningon women's lives in the district of Bamako, Mali. Fifty-five first-time users of contraceptives were interviewed in October 1996. Of particular interest is the high proportion (17/55) of those who had hidden their use of a birth-control method from their husbands. Substantial collusion is found to have occurred between sisters-in-law in assisting each other to gain and hide methods of family planning and to keep their use secret from their spouses and older marital relatives. The main reason for discontinuation among the clandestine users was menstrual disruption, which they feared would make their husbands aware of their contraceptive use. By the end of the study, women were aware that their use of contraceptives had increased their mobility and available time, enabling them to enhance the quantity and efficiency of their work activities. Contraception, therefore, appears to be a valuable resource, permitting women to improve their economic and social status. In settings where clandestine use is prevalent, at least in the short term involving men in family planning programs may not always be beneficial, nor may considering the couple as the unit of intervention and analysis always be appropriate. In the long term, however, the underlying causes of men's objections to contraceptive use need to be addressed so as to facilitate communication and joint decisionmaking about family planning