['The undertreatment of ethnic minority children with ADHD prompted a study on the effects of methylphenidate (MPH) on the executive functions of African American children with ADHD.', 'Nineteen African American children with ADHD are tested on the Tower of Hanoi (TOH) and the Paired Associates Learning Task (PAL) in a double-blind crossover acute challenge of MPH and placebo.', 'Under MPH, TOH rule breaks decrease, especially in the second testing session, and TOH planning time increases, particularly for incorrect solutions; PAL recall in the final learning trial improves with MPH.'] Does methylphenidate improve aspects of executive function in African American children with ADHD?