The authors performed 5-year prospective follow-up (retention rate = 92%) with an ethnically diverse sample of girls, aged 11-18 years, who had been diagnosed in childhood with attention-deficit/ hyperactivity disorder (ADHD; N = 140) and a matched comparison group (N = 88). Hyperactive-impulsive symptoms were more likely to abate than inattentive symptoms. Across multiple domains of symptoms and functional impairment, girls with ADHD continued to display deficits of moderate to large effect size in relation to the comparison girls, but few differences emerged between the inattentive versus combined types. Follow-up effects withstood statistical control of crucial covariates for most outcomes, meaning that there were specific effects of childhood ADHD on follow-up status; in other instances, baseline disruptive disorders accounted for adolescent effects. For outcomes identical at baseline and follow-up, girls with ADHD showed more improvement across time than comparison girls (except for math achievement). Overall, ADHD in girls portends continuing impairment 5 years after childhood ascertainment.