The death rate due to diarrhea in Indonesia reaches 7.4%. Based on a morbidity survey by the departement of health in 2009, mortality due to diarrhea in infants is 75/100,000 children. A mother's knowledge becomes important in handling diarrhea diseases because the fatal incidence of diarrhea is caused by negligence and late treatment. The government made efforts to approach / how to manage sick children by giving birth to MTBS. This effort combines improved case management in sick toddlers (curative) with aspects of nutrition, immunization and counseling (promotive and preventive). In order for MTBS to be implemented as expected, systematic and comprehensive steps are needed, as well as the integrity of the mother's role supported by her knowledge of diarrhea management as well as the role of MTBS officers so that the risk of death from diarrhea can be reduced. thus helping in efforts to equalize health services and open access for all levels of society to obtain integrated health services. This type of research is an analytic survey with cross sectional approach. With a population of 288 toddler mothers with a sample of 175, using a purposive sampling technique. Research instruments using questionnaires and data analysis using the chi square test. Based on the tests conducted showed a significant relationship between maternal knowledge and the role of MTBS officers with maternal behavior in handling diarrhea, with the Pearson Chi-Square test results of 41,917 and 54,315 and X2 table values with df = 4 a = 0.1 which is equal to 7,779 which indicates that X2 count> X2 table. which means that p <0.1. Thus it can be concluded that the higher the mother's knowledge and the better the role of the MTBS officer, the better the mother's behavior in handling diarrhea
