Precipitating stimuli were investigated in a 24-year-old woman with primary reading epilepsy. Reading material was presented on a microcomputer video display monitor under controlled conditions while the patient underwent EEG radiotelemetry/video monitoring. We examined the relative contribution of the following variables utilizing a factorial design: eye movements, reading aloud versus reading silently, linguistic complexity, and concentrations. None of these factors acted solely as the critical stimulus in provoking seizures. Seizures were most readily elicited when the patient read aloud, using material of medium or high linguistic complexity with the usual scanning eye movements for reading.