Flunarizine was tested for prophylactic efficacy and for side effects in 10- to 13-year-old patients with severe migraine (greater than 2 attacks per month). The 13 preadolescents received a single 5-mg dose at night for 2 months. The attack frequency decreased significantly, and the effect was maintained over time. The endocrine status, investigated before and after treatment, showed no significant interference with pituitary, beta-pancreatic, or gonadal function.