Objectives:
Comparison of the functioning of families of teens (13–16 years) with the diagnosis of attention deficit hyperactivity disorder (ADHD) or ADHD and oppositional defiant disorder (ODD).

Methods:
Assessment using the Family Assessment Questionnaire in three groups of adolescents growing up in biological families: (1) ADHD/ODD group (n = 40), (2) ADHD group (n = 40) and (3) group C (control group) adolescents (n = 40) who have not used psychological or psychiatric care in the past or at present.

Results:
Mothers, fathers and adolescents from the ADHD/ODD group scored significantly lower in all important aspects of family functioning compared to the control group. In the ADHD group, less favorable mother’s and father’s assessment was shown for all areas of family functioning compared with the control group. Adolescents’ assessment in the dimension of “Role performance”, “Emotionality”, “Affective involvement”, and “Control” was also lower. The ADHD/ODD group participants and their parents rated the functioning of the family lower compared with the ADHD group: mothers – in all described areas, teenagers – in most of the described areas except the dimension of “Control”, and fathers – in most areas except the dimension of “Emotionality”.

Conclusions:
The functioning of families of patients with ADHD and ODD, and families of patients with ADHD significantly differs in all or most of the examined dimensions compared with families of people without diagnosis, while the functioning of families of patients with ADHD and oppositional defiant patients can be described as more abnormal than that of families of ADHD patients.