It is often noted that some individuals become aware of a mass media program's messages through discussions with other individuals. However, the extent to which indirect exposure occurs, and its influence on behavior, are somewhat unclear. This study examines the role of indirect exposure in extending the reach of a family planning mass media campaign in Nepal. Sociometric data, gathered from nearly all women between the ages of 15 and 49 years living in six villages in Dang District, Nepal (N = 667), assessed indirect exposure to the radio program. Indirect exposure was extensive; half of all respondents were indirectly exposed to the program's messages and the overall reach of the program increased from 50% to 75% when indirect exposure was considered. Members of community groups had higher levels of direct exposure to the radio program and more extensive and diverse social networks, allowing them to serve as a conduit for these messages into the wider community. While direct exposure to the radio program appeared to influence family planning knowledge, indirect exposure was more strongly associated with contraceptive use. These findings suggest that program evaluations that ignore indirect exposure underestimate the impact of a mass media program on behavior.