We examined the applicability of attribution theory to mothers' perceptions and reactions to their child's problem behavior. Participants were 149 Latina mothers of children with developmental disabilities who were interviewed regarding specific incidents in which their child exhibited a behavior problem. The findings indicate that most mothers viewed their child as not being responsible for the behavior problem. Furthermore, as predicted by attribution theory, mothers who ascribed relatively high responsibility to the child were significantly more likely to report negative emotions (anger and frustration) and aggressive/harsh behavioral reactions than mothers who ascribed low responsibility. Also, mothers were more likely to ascribe high responsibility to the child when the problem was characterized as a behavioral excess than as a behavioral deficit. The results provide support for the applicability of an attributional framework and may have important implications for helping parents in addressing the problem behaviors of their children with developmental disabilities.