Physicians are asked to advise people with epilepsy whether consumption of aspartame (NutraSweet®) is safe and prudent. Aspartame is metabolized to l-phenylalanine, l-aspartate, and methanol. Each metabolite can produce toxic or excitatory effects in animal model systems but only at doses much higher than those feasible from human aspartame consumption. Secondary changes in brain levels of catecholamines and serotonin may occur because of competition precursor transport into brain; however, the clinical relevance of these changes is uncertain. In rodent models of epilepsy, aspartame may alter seizure thresholds when given in doses of 1,000 mg/kg, equivalent to consumption of about 400 diet soft drinks. Applicability of such animal data is questionable. Seizure thresholds in genetically photosensitive baboons are not altered by massive doses of aspartame. Scanty anecdotal clinical reports of overlaps between seizures and aspartame consumption have been published. Monitoring of consumer complaints by the Center for Disease Control and the Food and Drug Administration has failed to document an association of aspartame intake and epilepsy. No controlled clinical trials of aspartame in people with epilepsy have been published. Current evidence suggests that present consumption of aspartame does not induce brain damage, nor does it provoke seizures.