To determine the characteristics of multimodal evoked potentials (MEPs) in childhood-onset dentatorubral-palli-doluysian atrophy (DRPLA) we studied three DRPLA patients with progressive myoclonus epilepsy. Brainstem auditory evoked potentials showed reduced or absent brainstem components as well as delayed latencies. In addition, short latency somatosensory evoked potentials (S-SEPs) had prolonged central conduction time and reduced amplitude of cortical components. Two patients with symptom onset in the first decade of life had extremely enlarged flash visual evoked potentials with shortened latency even in the absence of giant SEPs. Therefore, children with progressive myoclonus epilepsy and the above MEP findings are likely candidates for childhood-onset DRPLA and should undergo DNA analysis for DRPLA.