Some researchers who have studied children with behavior problems have suggested that depressed mothers distort reports of deviance in their children, perhaps contributing to misdiagnoses; however, investigations studying mothers with current or past depression have not clearly indicated such a bias. Because some of this equivocation may be due to the confounding effects of the mother-child history, the present study examined maternal ratings of the standardized behavior of child confederates, thereby providing an objective standard from which bias could be determined. Maternal lifetime diagnoses of depression and contemporary reports of depressive symptomatology were also evaluated. Mothers of 4- to 12-year-old sons with attention-deficit/hyperactivity disorder (ADHD) interacted with and rated boys in the same age range whose behavior was carefully scripted to represent either ADHD or the absence of any disorder. Forty-four of these mothers had a history of clinical depression, and the entire sample represented a range of depressive symptomatology. Analyses revealed no significant differences in ratings of the child confederates' behaviors as a function of maternal history of depression or current depressive symptomatology. These findings thus call into question at least some of the prior assertions of maternal bias in the reporting of behavior problems in children.