Major obstacles to reducing fertility in Pakistan include social and religious objections to family planning. Understanding of the decision-making dynamics and identification of the fertility decision-maker in the household therefore is important if these obstacles are to be addressed. As a complementary effort to a larger study aimed at identifying fertility decision-maker, the decision making process and the factors that influence inter-spousal communication, keyinformant interviews were conducted in the squatter settlements of Karachi. Between June and August 1995 we interviewed 18 individuals in six families: three families in which the couple was currently using contraceptives and three families in which the couple had never used contraceptives. Using a set of semi-structured open ended questions, within each family, we interviewed a triad of three adults, consisting of a married woman, her husband and her motherin-law. Responses of the 18 individuals suggest that males and elderly women made decisions on family matters. Young women neither had the power to make decisions nor were they consulted on important matters. The decision to use contraceptives was dependent on husbands' approval although the method of contraception adapted was by mutual consent between spouses. Husbands and mothers-in-law in the contraceptive users households were not opposed to family planning practices although all respondents perceived that the society regarded family planning contradictory to the teachings of Islam. Compared to non-user families, contraceptive user families had a better understanding of the objectives and scope of family planning including contraceptive methods. They also reported a greater degree of inter-spousal communication. We assume that the pace of fertility decline may be enhanced by designing family planning programs that lend clarity to Islamic teaching on fertility control and providing family planning education and information specifically aimed at males.