This study demonstrates the efficacy of cyclosporine included in a regimen for the treatment of steroid-resistant chronic inflammatory demyelinating polyradiculoneuropathy in two children. Clinical response was characterized by either decreased frequency of recurrent weakness or normalized motor function. Nerve conduction studies and monitoring of cyclosporine levels were included in the serial follow-up evaluations, and their results were used in formulating a treatment plan. One of the two children, who had been monitored for 56 months since the onset of the disease, was able to maintain normal muscle strength without recurrent weakness for 39 months, with 5 mg/kg daily of cyclosporine. The other child, who had been taking prednisolone 0.3 mg/kg daily and cyclosporine 5 mg/kg daily, regained ambulation without support while demonstrating a reduction of recurrent weakness. None had adverse effects caused by cyclosporine therapy. We conclude that cyclosporine is an effective drug in the treatment of children with steroid-resistant chronic inflammatory demyelinating polyradiculoneuropathy.