This study compared 46 adopted adolescents (50% males) and their adoptive mothers respectively with 66 non-adopted peers (44% males) and their biological mothers both in psychopathological symptoms - measured by the Child Behaviour Checklist 6/18 and the Symptoms Checklist-90-Revised - and in emotion regulation strategies, such as cognitive reappraisal and expressive suppression, measured by the Emotion Regulation Questionnaire. Adopted adolescents showed more externalizing problems and used more expressive suppression than peers. No differences were found in mothers regarding psychopathology, but adoptive mothers reported more cognitive reappraisal than biological ones. In the adoption group, regression analysis showed that maternal levels of psychopathology predicted adolescents' externalizing problems, controlling for adolescents' gender and cognitive reappraisal. It suggests the importance both to screening maternal mental health before adoption and to offer post-adoption services for adoptive families.