Background: Stunting in toddlers is still a serious health problem in Indonesia. Clean and Healthy Living Behavior (PHBS) is one of the factors that influence the nutritional status of toddlers. Research Objective: To understand the relationship between knowledge of clean and healthy living behavior and the nutritional status of stunted toddlers in West Kupang Regency. Research Method: Using an analytical research design with a chi-square design, this study was conducted by collecting secondary data from the Community Care Network Foundation. The sampling was done using a cluster random sampling technique with a total of 100 respondents. The research was analyzed bivariately using the risk estimate test. Results: The majority of toddler subjects are male. The toddler subjects range in age from 0 to 4 years. The parents of the subjects have educational statuses of elementary school (16%), junior high school (19%), high school/vocational school (49%), and university (16%). The mothers of the subjects have occupations as housewives (85%), civil servants (4%), farmers (4%), and private employees (7%). Respondents with poor knowledge-behavior of clean and healthy living, based on exclusive breastfeeding, account for 19%, poor routine weighing at integrated health posts (Posyandu) 4%, poor childbirth assistance 44%, poor handwashing habits 37%, poor use of clean water 52%, and poor toilet usage 2%. Malnutrition status in toddlers is as follows: 62% underweight (Weight-for-Age), 23% stunted (Weight-for-Height), and 28% underweight (Body Mass Index-for-Age). Bivariate analysis results between knowledge-behavior of clean and healthy living show a significant relationship between exclusive breastfeeding and the use of clean water with the nutritional status of toddlers. Conclusion: There is a significant relationship between exclusive breastfeeding and the use of clean water with the nutritional status of toddlers.