The purpose of this study was to provide basic information on the development of nutrition education programs to improve the mealtime behavior of children with autism spectrum disorder (ASD) by investigating the mealtime behavior and food preferences of children with ASD through the perception of special education teachers. Surveys were given to 108 special education teachers in special education schools in Korea regarding the demographic characteristics, nutrition education support needs, mealtime behavior, and food preferences of children with ASD. Most of the special education teachers responded that nutrition education in special schools had not been conducted properly and nutrition education for ASD children is necessary. Mealtime behavior analysis classified the behavior into three clusters: cluster 1, ‘less problematic mealtime behavior’; cluster 2, ‘general feature of autism’; cluster 3, ‘difficulty in self-directed diet’. The age, eating habits, and food preferences were different according to each mealtime behavior cluster. Therefore, it will be necessary to develop a nutrition education program based on the characteristics of mealtime behavior.