The literature suggests that more than 60% of young offenders, in the USA and internationally, are screened positive for Attention Deficit Hyperactivity Disorder (ADHD). However, little scholarly attention is given to the role a defendant's diagnosis of ADHD plays in court proceedings and decisions. The current exploratory qualitative study involves thematic content analysis focused on twelve court decisions dated from 2000-2011, from various jurisdictions, involving young defendants with ADHD. The findings suggest courts' interpretation and treatment of the defendant's ADHD diagnosis varies across cases, jurisdictions, and phases of the legal procedure. Evidence regarding the diagnosis was not sufficient, in itself, for the courts to make decisions that incorporate consideration of the disorder's impact on the defendant's functioning or treatment needs. When experts testify about the impact of ADHD on a case-relevant behavior or aspect of the defendant's functioning, the court is more likely to take the disorder into consideration in its decision than when experts' testimony simply states that the defendant is diagnosed with the disorder. Courts' considerations for the defendant's diagnosis of ADHD were reflected mainly in decisions to adjudicate the defendant as a youth and in sentencing decisions. The findings suggest a need for greater collaboration and communication among professionals in the criminal justice and mental health systems, in order to better understand the role of ADHD in relationship to the various phases of the adjudicative process and to better serve the needs and rights of young defendants with ADHD.