This study describes temperament, personality, and problem behaviors in children with Attention-Deficit Hyperactivity Disorder (ADHD) aged 6 to 14 years. It targets differences between an ADHD sample (N = 54; 43 boys) and a large community sample (N = 465; 393 boys) in means and variances, psychometric properties, and covariation between traits and internalizing and externalizing problems. Parents rated their children on Buss and Plomin’s and Rothbart’s temperament models, a child-oriented five-factor personality model and also on problem behavior. Relative to the comparison group, children with ADHD presented with a distinct trait profile exhibiting lower means on Effortful Control, Conscientiousness, Benevolence and Emotional Stability, higher means on Emotionality, Activity, and Negative Affect, but similar levels of Surgency, Shyness, and Extraversion. Striking similarities in variances, reliabilities and, in particular, of the covariation between trait and maladjustment variables corroborate the spectrum hypothesis and suggest that comparable processes regulate problem behavior in children with and without ADHD.