The purpose of this study is to examine the predictive effect of preschooler's emotion understanding on social competence and internalized and externalized behaviors. A total of 95 children, 42 boys and 53 girls, attended the preschools in Üsküdar district of Istanbul Province. The Affect Knowledge Test and Social Competence and Behavior Evaluation Scale were used in the study. The analysis of the data was performed using multivariate multiple regression analysis. When the results of the t-test on the significance of the regression coefficients obtained as the result of the analysis are examined, it can be concluded that emotion understanding predicted the social competence such as seeking solutions to cooperation and disagreements that children have with their peers, it was also understood that emotion understanding did not predict the angeraggression and anxiety-withdrawal subscales of Social Competence and Behavior Evaluation Scale.