A random sample of 493 multiple sclerosis (MS) patients registered with the Northern California Chapter of the National MS Society was surveyed by mail and subsequently interviewed with regard to their MS, life style, diet, medical treatment, family history, and insurance coverage. Of this sample, 168 patients (34%) returned completed questionnaires. The answers on the questionnaire were entered into a database and scores on the extended disability status scale (EDSS), the neurologic rating scale (NRS), the ambulation index (AI), and the mean disability scale (MDS) were determined from the patient's answers to a portion of the questionnaire using a previously validated conversion program. This survey population of 168 patients seemed to represent well both the random sample and the frame population from which it was drawn. Patients commonly experienced symptoms for which there are medical treatments currently available such as bladder symptoms, fatigue, spasticity, pain, and depression. Surprisingly, however, with the exception of spasticity, patients were only infrequently treated for these complaints. In addition, despite the recent approval of the beta-interferons and copolymer I in the treatment of MS, only 74% of the appropriate candidates for such treatment had these options discussed with them and only 45% ever actually received such treatment. Certain clinical features and dietary habits were strongly associated with both EDSS scores and total disability. Not unexpectedly, either a progressive disease course or the presence of neurological dysfunction in any one of a number of functional areas (e.g. bladder, vision, cognitive change, etc.) correlated with higher EDSS scores and greater total disability. Fatigue was also strongly correlated with disability. Indeed, fatigue accounted (in whole or in part) for 65% of the disability experienced by patients; an observation which only underscores the fact that fewer than one third of the patients who experience fatigue have ever been tried on medications. Interestingly, the only factors associated with lower EDSS scores and less total disability were exercise and alcohol consumption. Such associations from a single survey, however, do not establish causation. It is the purpose of this study to establish a baseline level of function within this survey population so that future surveys in the same set of individuals can allow a prospective assessment of how health outcome has influenced different aspects of the patient's medical care, lifestyle, and insurance coverage.