Twenty-eight of 920 patients seen between the ages of 8 and 20 years for a first seizure manifested versive or circling events associated with bilateral rhythmic 3-cps spike-and-wave discharges. In 21 (75%), the seizures appeared between the ages of 10 and 14 years. Paroxysmal adversion or gyration was always toward the same side in a given patient. "Break of contact" during the ictus was found in 70% of the seizures, and secondary generalization occurred in half. Ictal electroencephalographic recordings failed to show a focal hemispheric origin. Additional features were: absence of prior major diseases; normal results of neurological and neuroradiological examinations; excellent response to anticonvulsant treatment with sodium valproate and/or phenobarbital; frequent family history of epileptic seizures (25% of patients); and association with generalized seizures (57.2% of patients). We conclude that versive or circling epilepsy with bilateral rhythmic 3-cps spike-and-wave discharges represents a benign form of primary generalized epilepsy in late childhood.