This study explores the difference in child emotion regulation (ER) and parenting between a heterogeneous clinical sample (ClinS) and a community sample (ComS). We hypothesized that parents of the ClinS would report more dysfunctional child ER and more dysfunctional parenting regarding the child’s negative emotions than parents of the ComS. Further, we aimed to predict child ER by parenting behavior, parents’ ER, and mental health. Parents of children and adolescents (aged 6–18 years) seeking treatment at an outpatient clinic were compared to a matched sample of parents in a ComS (n = 57 each group). As predicted, the children in the clinical group were reported to use less reappraisal and more suppression than ComS children. No difference was found in dysfunctional emotion parenting between the groups. Reappraisal in parents and supportive reactions to negative emotions predicted reappraisal in children. No predictor was found for child suppression. Child emotion regulation and parents’ psychopathology were not associated. These results could suggest new elements for prevention and intervention programs with parents concerning their own emotion regulation and their reaction to negative emotions in children.