The University of British Columbia Multiple Sclerosis (MS) Clinic was one of 11 North American sites involved in the double-blind, placebo-controlled phase III trial of Betaseron in relapsing-remitting MS. UBC participants as a unique sub-study site which required a rigorous evaluation every six weeks for the first two years. Each visit included extensive blood studies, neurological and physical exams by separate physicians. Magnetic Resonance Imaging (MRI) and evaluation by a research nurse. In addition, participants learned to administer the study medication subcutaneously every second day and keep extensive diaries of possible side effects, concomitant medications, neurological signs and symptoms, and incidental environmental events. The attrition rate was low (8%) despite the gruelling requirements of the study. As patients completed their course of therapy (and before unblinding took place) they were asked to complete a simple questionnaire about various aspects of the study. Questions explored their reasons for participation, helpfulness of preparatory information, positive and negative aspects during the trial, and their "guess" at what they were receiving. This paper will summarize the results of the questionnaires and offer suggestions for consideration when organizing long-term outpatient clinical trials.