We report on the outcome of intravenous high-dose immunoglobulin (IVIg) treatment in four children with narcolepsy and cataplexy, in whom the early diagnosis and the extreme disease severity were indications for this potentially efficacious therapy. One of four patients showed an objective and persistent improvement in clinical features during and after IVIg treatment. Our data partially support the recent report of the efficacy of IVIg treatment in early diagnosed narcolepsy with cataplexy and support the need for a controlled multicenter clinical trial on IVIg in narcolepsy.