Illicit sale of medicines is a serious public health problem in Africa. In Benin, an informational program was undertaken to fight this threat. A three-day survey on consumption of medicines was conducted in various areas in Cotonou. The purpose was to evaluate purchasing practices so that related concerns and beliefs could be used to craft messages for the next campaign to curb illicit medicines. In addition to being a tool for message development, this survey will be used as an evaluation tool to measure message impact during and after the information campaign. A questionnaire designed to evaluate several aspects of drug purchasing behavior was administered by investigators in 600 randomly selected households. The main findings were as follows. Repressive measures to reduce the sale of counterfeit medicines on the illicit market are necessary but inadequate. New campaign messages for targeted groups are necessary since 86% of people interviewed thought that medicines acquired from street vendors were of good quality. More importantly it will be necessary to make legitimate medicines more accessible and affordable (generic drugs) and to simplify dispensation procedures allowing prescriptions to be filled followed by appropriate professional counsel.