Epileptogenic paroxysms were studied in patients whose attacks were verified during prolonged recordings on the closed-circuit television-electroencephalogram (CCTV-EEG). Three types of complex partial seizures and four subvarieties of absence seizures were observed. All patients with complex partial seizures showed interictal spikes. Focal, low-voltage 8- to 30-Hz rhythms were most common during the onset of partial seizures in 64 patients, whereas diffuse spike-wave complexes appeared most often during generalized seizures in 26 patients. Relating the exact onset of clinical attacks on the videotape to depth electrographic events defined the local or diffuse origin of seizures in candidates for anterior temporal lobectomy.