We retrospectively studied 18 patients with West syndrome treated with ACTH according to Fukuyama's method. ACTH was given daily for the first 2 weeks, once every other day for the 3rd and 4th weeks, twice for the 5th and 6th weeks, and once a week for the 7th and 8th weeks. The patients were classified into two groups; group 1 (n = 9), in which Fukuyama's method was competed by a total of 27 injections; and group 2 (n = 9), in which Fukuyama's method was discontinued due to its adverse effects. In group 2, the duration of ACTH therapy was 15 days on average, and shorter than that in group 1. Between the two groups, there was no significant difference in the control rate of clinical seizures, and in the duration of therapy to attain seizure control (6 to 8 days on average). These results suggest that the tapering period is unnecessary after the cessation of spasms.