This is a study on popular ideas, beliefs and practices concerning the transmission and prevention of parasitic diseases, specifically schistosomiasis mansoni. The author explored the existence of a popular belief system within the health care system, combining elements from biomedicine and folk medicine for the understanding and management of the health/disease phenomenon. The study describes the differences in perception of morbidity and gender among the interviewwees. Finally, the study presents popular discourse on parasitic diseases and discusses diffculties with control measures. It considers the contradiction between cultural values and habits and conventional control measures, critically assessing the lack of precision in health education measures under government prevention programs.