Approximately 500 people were interviewed in a study designed to assess the effectiveness of and response-motivation to a public action campaign in a developing country. It focused on Nigeria's voter registration drive conducted in preparation for that country's first political elections in more than 13 years and explored some factors that influenced prospective voters' decisions to register and vote as well as their general attitudes toward the voting process. The results showed that radio, interpersonal contacts, and small group situations predominated both at the level of initial awareness and at the level of influence on personal decisions to register. Radio appeared almost as powerful as interpersonal forms at both of these levels. While 91% of those interviewed were registered and 100% said that they intended to vote, voter registration seemed to occur with little understanding of its purpose and benefits. The interpersonal factors seemed most effective in influencing such wide cooperation in the registration drive, but the people's experience with political upheavals in the past made them wary of the results of the elections. In addition, the campaign was one of information (telling people to vote) and not of communication (telling them why to vote). The findings suggest that more careful consideration needs to be given to the mentality and experience of the people to whom such massive public information efforts are directed. (Author/FL)