Objective: The present study was conducted with the aim of explaining children's behavioral disorders based on mothers' attachment styles. Method: Overall, 318 pre-school children (168 girls and 150 boys) were selected from the statistical society (which included the preschool centers of Isfahan City) by cluster random sampling. The required data were collected using the Achenbach' child behavior questionnaire (CBCL) – parents' version- and the Hazen and Shavar Attachment Styles Questionnaire. Data were analyzed by means of correlation and regression analysis. Results: The results showed that mothers' avoidant insecure attachment style was positively correlated with externalizing problems and internalizing problems while their ambivalent insecure attachment style and externalizing problems were positively correlated. Among the mothers' attachment styles, avoidant insecure attachment style had a positive role in predicting externalizing and internalizing problems in children. Conclusion: The findings showed that mothers with insecure attachment style have a significant effect on the development of behavioral disorders in children.