The aims of this study were to explore the feasibility of structured aerobic exercise followed by a period of unstructured physical activity and determine the impact of such exercise on cognition, mood, and quality of life in people with multiple sclerosis (MS). A convenience sample of 9 individuals with relapsing-remitting MS performed 30 minutes of aerobic exercise (upper- and lower-extremity ergometry and treadmill ambulation) twice weekly for 8 weeks, followed by 3 months of unstructured physical activity. Eight participants completed the intervention and posttest; 6 returned for the 3-month follow-up. Cardiovascular fitness, cognition, mood (measured with the Beck Depression Inventory-II; BDI-II), and quality of life (measured with the Multiple Sclerosis Quality of Life-54; MSQOL-54) were assessed. Participants completed 27.9 minutes of exercise per session, with an 85.1% attendance rate. Evaluation using the Wilcoxon signed rank test revealed no deleterious effects and improved results on the BDI-II and MSQOL-54 mental subscale. Analysis of change scores using the one-sample t test revealed that the BDI-II and MSQOL-54 were changed from zero after structured exercise, but only the BDI-II maintained improvement after unstructured physical activity. Further analysis of BDI-II subscales revealed that improvement occurred only in the Somato-Affective subscale. In this study, program feasibility was demonstrated in several ways. There were no declines in cognitive function over the 5-month period. Despite unchanged cognitive function, participants may value the improved mood enough to continue both the structured and unstructured physical activity. The role of unstructured physical activity in concert with periodic structured exercise programs merits further investigation.