Up-to date information about corticotropin (ACTH) in the treatment of infantile spasms and evaluation of the long-term outcome was provided to answer questions about (1) the efficacy of doses of ACTH in comparison with other drugs, especially with vigabatrin, and the efficacy in patients with tuberous sclerosis; (2) tolerability; and (3) long-term outcome. In two studies, high doses were not more effective than low doses but were more effective in another study. In the follow-up of the studies, there was no difference. In an open, randomized, prospective study, the efficacy and relapse rates of ACTH and vigabatrin treatment did not differ significantly. The high response rates in tuberous sclerosis complex were similar. Both drugs had severe side effects. In the long-term follow-up of 20 to 35 years, one third of the patients died, the intellectual outcome of the remaining patients was normal or slightly subnormal, and one quarter and one third of the patients were seizure free. ACTH should be the first choice for treatment of infantile spasms. The side effects of ACTH, unlike those of vigabatrin, are well known, treatable, and reversible. However, an open, prospective study to compare the efficacy, relapse rate, and long-term outcome of treatment with ACTH and vigabatrin is urgently needed. The frequency of visual field defects after vigabatrin therapy should be evaluated. ( J Child Neurol 2004;19:401-404).