The purpose of this study was to investigate the role of mothers’ depression, anxiety, stress and parenting styles in their children’ s oppositional defiant and conduct behaviors. The statistical population consisted of mothers of elementary school boys with such disorders in Shiraz. First, 4 elementary schools were selected by multi-stage cluster random sampling. Then, based on teacher and parents Child Symptom Inventory, 105 mothers of children with disruptive behaviors were selected. Participants completed Alabama Parenting Questionnaire and Depression, Anxiety, and Stress Scales. Data were analyzed using Pearson correlation and simultaneous regression. Findings of correlations showed a significant positive relationship between depression, anxiety, stress, inconsistency in parenting and poor supervision of mothers, with children’ s symptoms of oppositional defiant and conduct behaviors; also there is a significant negative correlation between mothers' positive parenting with children’ s oppositional defiant behaviors. Regression analysis indicated that maternal depression was the strongest predictors of children’ s oppositional defiant behaviors, while poor supervision was the strongest predictor of children’ s conduct symptoms. As a whole, the results revealed that depression, anxiety, stress and parenting methods of parents have significant relationship with oppositional defiant and conduct behaviors. These findings can be routinely addressed either in the therapeutic field or in the education of parents of children with oppositional defiant and conduct behaviors.