Sydenham's chorea is a neurological disease that appears in people with rheumatic fever, usually in childhood. It is a possible long term complication of a streptococcal infection. The disease is usually latent and shows up to 6 months after the acute infection, but it may occasionally be the symptom of rheumatic fever's presentation. Sydenham's chorea occurs more frequently in the female sex and most patients are at under 18 years of age. We report the case of a 13 year-old female patient, without significant pathological findings, who was brought to our observation for having presented involuntary movements of the head and arms associated with important difficulty in speech for about 4 days. After a complete neurologic and psychiatric evaluation, blood and instrumental examinations, we make diagnosis of Sydenham's chorea and established a specific farmacologic plan of therapy, at first with AED (anti-epileptic drugs), and then with Haloperidol with an initial benefit. During the follow up, due to the recurrence and the persistence of the symptoms, we decided for a switch of therapy, using Aripiprazole, with a very important and long-lasting amelioration, with practically complete extinction of involuntary movements.