Multiple sclerosis (MS) is a complicated neurological disease with an unknown cause and cure. Ongoing research efforts have produced several theories which are helping scientists identify clues to the etiology of the disease, as well as assist in the development of experimental treatment modalities. Current information regarding the possible underlying causes of MS as well as several of the experimental treatments under investigation are presented in this article. The nurses' role in helping persons with MS and their families during the decision-making phase of experimental treatment is discussed. Selected nursing diagnoses, goals and interventions are described in order to provide guidelines for practitioners managing the care of persons receiving experimental treatments in MS.