Two surveys were conducted to examine the cognition of externalizing problems by early childhood education and care (ECEC) teachers, and the effectiveness of feedback on cognitive tendencies. Survey 1 administered a questionnaire to ECEC teachers on the description of a 5-year-old child’s daily situation at the ECEC to examine their cognition of the severity, burden, background factors, and correspondence with the externalizing problems and their relationship to childcare. The analysis of the 77 open-ended responses generated six categories of background factors for externalizing problems, as recognized by ECEC teachers, and ten categories of correspondence. The results showed that the more group-cohesion-oriented teachers were, the higher they recognized the severity and burden of actions related to externalization. In childcare, emphasizing the needs of each child, and behaviors related to externalizing problems were considered less severe. These teachers tended to reflect on the relationships in the ECEC, and chose environmental adjustment over direct instruction, based on their understanding of the child. In Study 2, the results of Study 1 were used as feedback to analyze the relationship between the effectiveness of feedback and daily reflections. There were 80 participants in the analysis. The mean score for effectiveness was 4.89 (on a 6-point scale), indicating that the feedback was generally effective. The higher the reflection score, the higher the score of effectiveness. Based on these results, support for ECEC teachers is important to prevent the vicious cycle surrounding externalizing problems.