This paper reviews existing publications on the use of piracetam for the treatment of cortical myoclonus of various etiologies and includes the personal experience of the authors in progressive myoclonus epilepsy. Two double-blind comparisons with placebo provided results which allow recommendations for the dosage and usage of piracetam in cortical myoclonus. Wide individual variation (7-24g daily) exists in dosage requirements but responses are dose-related so that dosage should be increased until an optimum effect is obtained. Tolerability after long-term use of piracetam in high dosage has been very good and without toxicity or serious adverse effects. Side effects have been occasional, mild and transient. The authors present their experience of 12 patients with progressive myoclonus epilepsy in whom the administration of up to 45 g piracetam daily, when added to existing anti-epileptic treatment, caused marked and sometimes spectacular improvement and was without significant adverse effects. Improvement was maintained for up to 7 years. The use of piracetam for disabling cortical myoclonus of any etiology, either as an addition to existing antimyoclonic drugs or as monotherapy, may bring about profound improvement in disability and quality of life. Piracetam should be considered a first-line drug for the treatment of cortical myoclonus.