Context: Family planning communications campaigns have been shown to increase contraceptive use, but it remains unclear whether exposure to messages about contraception through multiple media sources has a greater impact than exposure through one medium. Methods: Data from a nationally representative sample of 4,225 women who participated in the 1994 Tanzania Knowledge, Attitudes and Practice Survey and in the 1991-1992 Tanzania Demographic and Health Survey were used to assess the impact of mass media family planning campaigns on contraceptive behavior. A bivariate analysis was conducted to study the association between social and demographic characteristics, family planning communications campaigns and contraceptive behavior; multiple regression analysis was used to examine the relationship between specific media campaigns and contraceptive use. Results: The more types of media that women are exposed to, the more likely they are to practice contraception. Women who recalled six media sources of family planning messages were 11 times as likely as women who recalled no media sources to be using modern contraceptives. Even women who recalled only one media source with a family planning message were twice as likely as women who recalled no media source to be using a modern method. Women who recalled family planning messages in the media were also more likely to have discussed family planning with their spouse and to have visited a health facility than were women who could not remember any such intervention. After introduction of controls for other variables, women who recalled radio messages about family planning were 1.7 times as likely as women who reported no exposure through radio programs to have discussed family planning with their spouse and were 1.9 times as likely to have been currently using family planning. Conclusions: Multiple media sources of information on contraception reinforce one another and extend the reach of a family planning campaign. Complementary messages may help to create an environment where the practice of contraception is perceived as a social norm. Varied media should continue to be used to promote family planning and other reproductive health issues.