The anti-epileptic effect of vigabatrin as a first choice therapy was investigated in 6 children suffering from infantile spasms (IS). All 6 children showed a reduction in seizure frequency. Three children became seizure-free within a period of 2 weeks. Because our results suggest "an all or nothing phenomenon", a period of 2 weeks may be sufficient to evaluate the efficacy of vigabatrin in untreated infants suffering from IS. We suggest to use vigabatrin as a first choice anti-epileptic drug in infants with IS.