ABSTRACT Hunger and malnutrition cause the highest death rates worldwide. At least 17,289 children die every day due to hunger and malnutrition. Based on data of the 496 districts / cities in Indonesia, 404 districts / cities have acute-chronic nutritional problems, 20 districts / cities have chronic nutritional problems, 63 regencies / cities have acute nutritional problems and 9 districts / cities that do not found nutritional problems (MOH, 2017). The purpose of this health education is to increase the knowledge of mothers about malnutrition in children under five in Sindangsari Village, Cimerak District, Pangandaran Regency through health education. As well as identifying the mother's knowledge after giving health education about malnutrition to toddlers. The case taking method used is the health education method. According to Notoatmodjo (2012) health education is all activities to provide and increase knowledge, attitudes, practices for individuals, groups or communities in maintaining and improving their own health. From the results of health education, it can be seen that the knowledge of mothers about malnutrition among toddlers in Sindangsari Village, about before health education was implemented, most of them had less knowledge (66.7%). After the implementation of health education, most of them have good knowledge (77.77%). It can be seen the average value before health education (60.5%). and after health education (88%). There was an increase (27.5%).