We investigated relationships among parenting stress, parental readiness to change, and child externalizing behaviors in a sample of clinically referred families. Additionally, parenting stress was investigated as a potential moderator of the relationship between parental readiness to change and child externalizing behaviors. Sixty-nine parents of clinically referred children completed measures of parenting stress, readiness to change, and child externalizing behaviors. We found that child externalizing behaviors, specifically hyperactivity/impulsivity and oppositionality, had a significant positive relationship with parental readiness to change and parenting stress. Child conduct disorder symptoms did not significantly relate to parental readiness to change. Parenting stress emerged as a significant moderator of the relationship between child externalizing behaviors and parental readiness to change, such that at low levels of parenting stress, readiness to change increased as level of child externalizing behaviors increased. However, at high levels of parenting stress, parental readiness to change remained high and constant irrespective of level of child externalizing behaviors. The findings from this small pilot study have significant implications for clinicians and researchers. The parents most ready to engage in child mental health services may be those with high levels of parenting stress, regardless of the severity of the child's behaviors. These parents may benefit from learning stress management strategies in addition to receiving intervention services for their children. Researchers should further examine the clinical utility of measuring readiness to change in families of children with behavior problems.