Modifiable lifestyle risk factors for progression of multiple sclerosis (MS) have been increasingly studied. This study employed a single-group design involving a one-off intensive live-in educational workshop on lifestyle modification for people with MS. We aimed to examine changes in a range of clinical and lifestyle variables and quality of life, self-efficacy, physical impact of MS and disability from baseline to 3- and 5-years post-intervention. 95 participants completed the baseline survey. Data included lifestyle risk factors of diet quality, meat and dairy consumption, omega 3 and vitamin D supplementation, physical activity, stress reducing activities, and smoking status, and use of disease-modifying therapies (DMTs). Patient-reported outcomes included health-related quality of life, self-efficacy, physical impact of MS and disability. Generalised estimating equation models were used to account for within-participant correlation over time. Sixty participants (63.2%) provided data at 3- and 5-years. Significant improvements in diet quality, omega 3 supplementation, and non-smoking were seen at both timepoints. Use of DMTs and disability remained unchanged. Mental (8.8- and 6.9-point) and physical (10.5- and 7.3-point) quality of life, and self-efficacy (2.4- and 1.9-point) improved significantly at 3- and 5-years, respectively. Physical impact of MS reduced from baseline to 3-years (-3.7 points) with a trend towards reduction at 5-years (-2.9 points; p = 0.079). Education on lifestyle modification can lead to lifestyle modification and short and long-term improvements in mental and physical wellbeing outcomes. Results suggest potential value in lifestyle modification as an adjunctive component to standard therapy for MS.