Aim: This study examined the influence of teachers, mothers, and children themselves on weight misperceptions of preschool children. Background: Preschool children should have correct perceptions of their weight and develop a positive body image and healthy weight-control behaviors throughout childhood. Methods: This study used a descriptive cross-sectional design based on the biopsychosocial model. We analyzed 388 triads of Korean children aged 3-6 years, their mothers, and teachers. Results: Children's body mass index (BMI) and weight satisfaction, mothers' BMI; teachers' education level, BMI, perception of and satisfaction with children's weight, body image, and attitude toward obesity were predictors of children underestimating their weight. Mothers' education level and BMI; teachers' BMI, satisfaction with children's weight, and body image were predictors of children overestimating their weight. Conclusions: Teachers influence weight misperceptions of preschool children. Intervention programs for teachers should incorporate more accurate perceptions of children's weight and promote healthy body image. (author abstract)