The vast majority of the patients with dystonia have obscure causes. We present 2 cases of neuronal heterotopia in the basal ganglia, who developed contralateral hemi-dystonia and other nervous system abnormalities in early childhood. The first case was a premature female infant who developed involuntary twist movements of the left arm, persistent plantar flexion and eversion of the left foot at age of 7 months. All of the symptoms disappeared during sleep. Delayed motor milestones were also noted. She was still not able to stand or sit steadily at the age of 17 months. The CT scan of brain revealed a nodular lesion at the margin of right lateral ventricle, which was not enhanced by contrast medium suggesting neuronal heterotopia. Besides, smooth cortical surface, poorly recognizable cortical sulci, agenesis of corpus callosum and dilatation of lateral ventricles were also noted. The second case was a 21-year-old man with involuntary movements of left side body and limbs since his early childhood. He had persistent twist and intermittent jerky movements of the left limbs and torticollis. The patient also showed dysarthria and mild mental retardation. The CT scan of brain showed a heterotopic nodule at the margin of right lateral ventricle. The 2 cases reported here suggest that the early onset of hemi-dystonia with multiple nervous system disorders and the abnormal neuronal migration in human embryonic stage are related.