Introduction: Studies have shown that parents of children with pervasive developmental disorders (PDD) exhibit higher levels of stress than parents of typically developing children or children with other types of developmental delays (DD). This relationship appears to be mediated by elevated levels of behavior problems observed in children with PDD. However, little is known about what specific child behavior problems are most common in this population or how these behavior problems relate to parental stress. We examined the relationship between parenting stress and child behavior problems in parents of young children with PDD. Method: The current study utilized data from the Mindful Awareness for Parenting Stress (MAPS) project and included 72 parents of children with PDD. The mean age of the parents in the current study was 34.81 years (SD = 7.67) and the mean age of the children was 3.86 years (SD = 0.98). Results: The most commonly endorsed classes of child behavior problems included attention problems, language problems, and externalizing behavior problems. Three specific behavior problems, "Doesn't answer when people talk to him/her," "Speech problem," and "Temper tantrums or hot temper," were significantly related to parental stress levels at intake. Furthermore, these three behavior problems uniquely predicted parenting stress. Conclusions: Identifying the behavior problems that are most difficult for parents to handle may allow clinicians to tailor interventions to the specific needs of families. The current study indicated that social difficulties, speech problems, and tantrums have the greatest negative impact on parental stress, highlighting these problems as ideal targets for interventions.