This study is a first-level evaluation of a family intervention targeted at adolescents with social, emotional and behavioural difficulties (SEBD) attending Child and Adolescent Mental Health Services (CAMHS) in Ireland. It is a combined implementation of the Working Things Out adolescent programme and the Parents Plus Adolescent Programme (WTOPPAP). METHOD: A total of 93 adolescents aged 11-17 years (M = 14.64, SD = 1.31; 39% male) and their parents took part in the study. The study used a quasi-experimental One-Group Pretest-Posttest design to assess change from pre- to post-intervention using the Strengths and Difficulties Questionnaire, the McMaster General Functioning Scale, Goal Attainment, Parent Stress Scale and the Kansas Parenting Satisfaction Scale. Both parent- and adolescent-rated goal attainment and general family functioning improved from pre- to post-intervention. Parents also rated their satisfaction with parenting as having significantly improved. Adolescent-rated emotional difficulties significantly improved for the overall sample and parent-rated child total difficulties for female adolescents significantly improved from pre-test to post-test. Parents of female adolescents also reported a significant drop in parental stress. These findings indicate that the WTOPPAP may be an effective intervention for adolescents with SEBD, particularly females, and their parents. Further implications are discussed.