BACKGROUND: Balance, mobility impairments and falls are common problems for people with multiple sclerosis (MS). Our ongoing research has led to the development of Balance Right in MS (BRiMS), a 13-week home- and group-based exercise and education programme intended to improve balance and encourage safer mobility. OBJECTIVE: This feasibility trial aimed to obtain the necessary data and operational experience to finalise the planning of a future definitive multicentre randomised controlled trial. DESIGN: Randomised controlled feasibility trial. Participants were block randomised 1 : 1. Researcher-blinded assessments were scheduled at baseline and at 15 and 27 weeks post randomisation. As is appropriate in a feasibility trial, statistical analyses were descriptive rather than involving formal/inferential comparisons. The qualitative elements utilised template analysis as the chosen analytical framework. SETTING: Four sites across the UK. PARTICIPANTS: Eligibility criteria included having a diagnosis of secondary progressive MS, an Expanded Disability Status Scale (EDSS) score of between ≥ 4.0 and ≤ 7.0 points and a self-report of two or more falls in the preceding 6 months. INTERVENTIONS: Intervention - manualised 13-week education and exercise programme (BRiMS) plus usual care. Comparator - usual care alone. MAIN OUTCOME MEASURES: Trial feasibility, proposed outcomes for the definitive trial (including impact of MS, mobility, quality of life and falls), feasibility of the BRiMS programme (via process evaluation) and economic data. RESULTS: A total of 56 participants (mean age 59.7 years, standard deviation 9.7 years; 66% female; median EDSS score of 6.0 points, interquartile range 6.0-6.5 points) were recruited in 5 months; 30 were block randomised to the intervention group. The demographic and clinical data were broadly comparable at baseline; however, the intervention group scored worse on the majority of baseline outcome measures. Eleven participants (19.6%) withdrew or were lost to follow-up. Worsening of MS-related symptoms unrelated to the trial was the most common reason ( = 5) for withdrawal. Potential primary and secondary outcomes and economic data had completion rates of > 98% for all those assessed. However, the overall return rate for the patient-reported falls diary was 62%. After adjusting for baseline score, the differences between the groups (intervention compared with usual care) at week 27 for the potential primary outcomes were MS Walking Scale (12-item) version 2 -7.7 [95% confidence interval (CI) -17.2 to 1.8], MS Impact Scale (29-item) version 2 (MSIS-29vs2) physical 0.6 (95% CI -7.8 to 9) and MSIS-29vs2 psychological -0.4 (95% CI -9.9 to 9) (negative score indicates improvement). After the removal of one outlier, a total of 715 falls were self-reported over the 27-week trial period, with substantial variation between individuals (range 0-93 falls). Of these 715 falls, 101 (14%) were reported as injurious. Qualitative feedback indicated that trial processes and participant burden were acceptable, and participants highlighted physical and behavioural changes that they perceived to result from undertaking BRiMS. Engagement varied, influenced by a range of condition- and context-related factors. Suggestions to improve the utility and accessibility of BRiMS were highlighted. CONCLUSIONS: The results suggest that the trial procedures are feasible and acceptable, and retention, programme engagement and outcome completion rates were sufficient to satisfy the a priori progression criteria. Challenges were experienced in some areas of data collection, such as completion of daily diaries. FUTURE WORK: Further development of BRiMS is required to address logistical issues and enhance user-satisfaction and adherence. Following this, a definitive trial to assess the clinical effectiveness and cost-effectiveness of the BRiMS intervention is warranted. TRIAL REGISTRATION: Current Controlled Trials ISRCTN13587999. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in ; Vol. 23, No. 27. See the NIHR Journals Library website for further project information.