Diarrhea is one of the major public health problems in Indonesia. The high incidence of diarrhea can be affected by several factors such as lack of knowledge and treatment of diarrhea in children under five years old. Giving information of diarrhea management can reduce its incidence on children. The objective of this study was to determine the influence of counseling for the treatment of diarrhea to the knowledge and attitude of mothers to bring children under five years to Primary Health Care. The method used in this research is a quasi-experimental method. Mothers with children were taken as Subjects. A simple random sampling was used to choose 96 subjects then given questionnaires about the knowledge about the treatment of diarrhea. The results was analyzed using the Wilcoxon test and shows the significant value of under 0.001. The less than 0.05 significant value shows differences in knowledge and attitude before and after given information. The level of mother knowledge about the treatment of diarrhea after given counseling higher than the mother's knowledge about the treatment of diarrhea before being given counseling.