Background: Recent exercise guidelines for people with multiple sclerosis (MS) recommend a minimum of 30 min moderate intensity aerobic exercise and resistance exercise twice per week. This trial compared the secondary outcomes of a combined 10-week guideline based intervention and a Social Cognitive Theory (SCT) education programme with the same exercise intervention involving an attention control education.Methods: Physically inactive people with MS, scoring 0-3 on Patient Determined Disease Steps Scale, with no MS relapse or change in MS medication, were randomised to 10-week exercise plus SCT education or exercise plus attention control education conditions. Outcomes included fatigue, depression, anxiety, strength, physical activity, SCT constructs and impact of MS and were measured by a blinded assessor pre and post-intervention and 3 and 6 month follow up.Results: One hundred and seventy-four expressed interest, 92 were eligible and 65 enrolled. Using linear mixed effects models, the differences between groups on all secondary measures post-intervention and at follow-up were not significant. Post-hoc, exploratory, within group analysis identified improvements in both groups post intervention in fatigue (mean Delta(95% CI) SCT -4.99(-9.87, -0.21), p = 0.04, Control -7.68(-12.13, -3.23), p = 0.00), strength (SCT -1.51(-2.41, -0.60), p < 0.01, Control -1.55(-2.30, -0.79), p < 0.01), physical activity (SCT 9.85(5.45, 14.23), p < 0.01, Control 12.92(4.69, 20.89), goal setting (SCT 7.30(4.19, 10.4), p < 0.01, Control 5.96(2.92, 9.01), p < 0.01) and exercise planning (SCT 5.88(3.37, 8.39), p < 0.01, Control 3.76(1.27, 6.25), p < 0.01) that were maintained above baseline at 3 and 6 month follow up (all p < 0.05). Only the SCT group improved at 3 and 6 month follow up in physical impact of MS(-4.45(-8.68, -0.22), -4.12(-8.25, 0.01), anxiety(-1.76(-3.20, -0.31), -1.99(-3.28, -0.71), depression(-1.51(-2.89, -0. 13), -1.02(-2.05, 0.01)) and cognition(5.04(2.51, 7.57), 3.05(0.81, 5.28), with a medium effect for cognition and fitness (Hedges' g 0.75(0.24, 1.25), 0.51(0.01, 1.00) at 3 month follow up.Conclusions: There were no statistically significant differences between groups for the secondary outcomes once age, gender, time since diagnosis and type of MS were accounted for. However, within the SCT group only there were improvements in anxiety, depression, cognition and physical impact of MS. Exercising at the minimum guideline amount has a positive effect on fatigue, strength and PA that is sustained at 3 and 6 months following the cessation of the program.