Benign myoclonus of early infancy (BMEI) is a non epileptic paroxystic disorder unknown in our pediatric population. We analyze the clinical characteristics in two patients with BMEI, and emphasize their differential diagnosis in four groups: encephalopathies with a non epileptic myoclonus, myoclonus without encephalopathy and without epilepsy, epileptic encephalopathies with myoclonus seizures and myoclonic epilepsy without encephalopathy. We consider to the BMEI as an autolimited, age-dependent, non epileptic paroxystic disorder without encephalopathy with onset in the early infancy. This study could be useful in order to identify the BMEI and avoid the incorrect use of antiepileptic drugs in our patients.