Extended-release guanfacine (Intuniv(TM)) is a novel long-acting, once-daily formulation of guanfacine indicated for attention deficit hyperactivity disorder (ADHD) in 6 to 77 year old children and adolescents. In doses 1 to 4 mg/day, guanfacine extended release (GXR) significantly improves the symptoms of inattention and hyperactivity-impulsivity in ADHD youngsters compared with placebo. Because of different pharmacokinetics, GXR is not substitutable on a mg-for-mg basis with immediate release guanfacine. Although extended release guanfacine does not demonstrate clinically significant ECG changes, mild slowing of the heart rote and some lowering of SBP and DBP does occur and requires vital sign monitoring during treatment. Children with a clinically significant cardiovascular history are not eligible for GXR therapy. Future research is exploring GXR effectiveness in ADHD complicated by oppositional defiant symptoms, ADHD complicated by tic disorders, posttraumatic stress disorders, and impulsive aggression in ADHD youngsters.