Three hundred fifty children (younger than age 16) who had familial Mediterranean fever (FMF) were given continuous prophylactic treatment with colchicine (1-2 mg/day) for 6-13 years. Complete remission of febrile attacks was achieved in 64% of the patients, and partial remission in 31%. Protracted attacks of arthritis virtually disappeared. None of the children developed amyloidosis while on the colchicine regimen. Side effects of colchicine were insignificant, and did not prompt permanent discontinuation of treatment in any of the children. Their growth, development, and subsequent fertility were normal. The efficacy of long-term colchicine treatment of children with FMF makes early diagnosis life saving.