Paroxysmal choreoathetosis (PC) is a rare entity, and professionals who study movement disorders do not find it easily. Paroxysmal occurrence of dystonic, choreic, athetosic movements is the typical feature of this syndrome. The onset is always subtle and the attacks can last from few seconds to hours. Sporadic cases and more common familial cases have been reported. The therapeutic approach with anticonvulsant drugs like carbamazepine is not always successful. However, there is a good response to this drug in the kinesigenic form of PC. The case of a 21 years old male patient is reported here. The onset occurred during puberty, at 14 years old. Neurologic examination was normal between attacks. Subtle and brief choreic, athetosic and dystonic limb and legs movements precipitated by sudden quick and unexpected passive movements, as by startle, were observed during the attacks. There was no familial history. Routine laboratorial investigation, EEG, CT scan and MRI did not show significant changes. Carbamazepine in low dosages (100 mg/day) brought a complete control of the attacks.