Attachment styles are considered as an important predictor of marital issues. The purpose of this study was to investigate the role of attachment styles in marital disillusionment and attitude toward infidelity. The research method was correlation. 188 teachers were selected based on measurement scale and research hypothesis by multistage cluster sampling among married teachers. Measures of adult attachment styles (Hazan & Shaver), marital disillusionment scale (Niehuis & Bartell) and attitudes toward infidelity scale (Whatley) were used. The results showed that secure attachment style and ambivalent attachment predict significant effect on marital disillusionment, but avoidant attachment doesn’t predict significant effect on marital disillusionment. Only avoidant attachment style have significant predictive effect on attitudes toward infidelity and also secure attachment and ambivalent doesn’t have significant predictive effect attitudes toward infidelity. Attachment styles influence an important part of the marital relationships. Thus, the role of secure and ambivalent attachment styles in marital disillusionment and avoidant attachment roles in infidelity should be taken deeper consider by researchers.