This report describes a 1979 study of the effectiveness of "merolicos"--Mexican medicine showmen--in disseminating health-related information to rural and urban populations with varying amounts of education. It is noted that five showmen were chosen and trained to disseminate a multi-part message on the nutrition of infants in six Mexican communities, and that interviews with mothers in these and six other control communities were later conducted to evaluate the impact of the medicine shows. The merolicos' nutrition message is described as containing, among other items, a recommendation for mothers to cleanse their breasts with camomile tea; the idea of a "magic meal" of beans and tortillas for infants aged 3 months and older; and the name and function of colostrum, the first breast secretion. Data are presented on the impact of these three items only. The results reported indicate that merolicos were able to change people's knowledge, attitudes, and behavior; that medicine showmen were effective in both rural and urban areas; and that the more educated also listened to and were influenced by the merolicos. It is recommended that medicine showmen be integrated into ongoing public health programs. A list of seven references and information about the authors of the report are attached. (ESR)