Prevalence rates of behavioral problems in children with motor disabilities are commonly based on questionnaires developed for a general population (e.g., Child Behavior CheckList). These questionnaires do not take into account lower levels of intellectual functioning. The first aim of this study was to examine the prevalence of parent-reported and daily caretaker-reported behavioral problems in children with motor and intellectual disabilities (MID) using the Developmental Behavior Checklist. Second, we investigated whether behavioral problems were related to sex and age. Our third and fourth aim were to determine whether behavioral problems are related to maladaptive personality traits and to marital stress and conflict. Participants were 101 Flemish children with MID (mean age = 14 years 6 months). For total behavioral problems, we found prevalence rates of 18% and 8% based on parent and daily caretaker reports, respectively. Based on parent reports, twenty seven percent of the children with MID exhibited anxiety problems. Behavioral problems were not related to sex. Older children showed fewer behavioral problems than younger children. Multiple hierarchical regression analyses revealed that lower scores on Compulsivity and higher scores on Emotional Instability and Disagreeableness were related to behavioral problems. In addition to personality traits, stress and conflict in the marital relationship was also positively associated with behavioral problems. Given the importance of behavioral problems in children with MID, this study is of theoretical and clinical interest and has the potential to inform targeted clinical interventions. (Contains 6 tables.)