- (1) Background: Schools report a high number of schoolchildren with poor attention and hyperactive behavior, with 5% being diagnosed with attention deficit/hyperactivity disorder (ADHD). This causes specific problems during homework and classroom times, and the extension of all-day schooling in German primary schools makes this a challenge for support staff working in the after-school programs. Such staff have a very wide variety of qualifications, ranging from no formal teacher training to full teaching qualifications. (2) Methods: This study documents the knowledge of 196 support staff working in all-day primary schools about ADHD, and their subjective view of whether they feel competent with regard to homework situations in general and ADHD in particular. (3) Results: Those with an educational background have significantly more knowledge than those without such a background, staff feel less prepared to supervise children with ADHD, and there is a small but significant correlation here with knowledge about ADHD. (4) Conclusions: The importance of trained pedagogical staff in the supervision of children with concentration problems is emphasized.