B BACKGROUND: Diarrhea is one of the leading causes of under-five mortality worldwide. Diarrhea is defined as bowel movements with a soft to liquid consistency with a frequency of 3 or more times within 24 hours. Diarrhea can cause children to experience malnutrition and even death if not handled properly. Apart from malnutrition, the incidence of diarrhea also often accompanies children with measles, and the status of measles immunization dramatically affects the condition of a child. This study aims to determine the relationship between nutritional status and measles immunization status with the incidence of diarrhea in toddlers.METHODS: This study used a cross-sectional analytic observational study design. The selection of subjects used the consecutive sampling method, with collecting 139 respondents at the Grogol Petamburan Primary Center, West Jakarta, in November 2022. Data were collected by interview using a questionnaire for measles immunization status with the incidence of diarrhea and measuring weight and height directly. The data is analyzed using the chi-square statistical test.RESULTS: Respondents who participated in this study were 139, of which 67 respondents (48.2%) had an undernutrition status, 59 respondents (42,4%) had a normal nutritional status, and 13 respondents (9,4%) had an overnutrition status. A total of 100 respondents (71.9%) had measles immunization status, and as many as 80 respondents (57.6%) experienced diarrhea. The results of the chi-square statistical test showed that there was a relationship between nutritional status and the incidence of diarrhea (p=0.003), and there was no relationship between measles immunization status and the incidence of diarrhea (p=0.553).CONCLUSIONS: There are correlations between nutritional status and the incidence of diarrhea in under-fives, and there is no significant relationship between measles immunization status and the incidence of diarrhea in under-fives.