Objective: To undertake a qualitative investigation of exercise perceptions and experiences in people with MS (PwMS) before, during and after participation in a personally-tailored program designed to promote long-term maintenance of self-directed exercise. Design: Focus groups and semi-structured telephone interviews. Setting: University Exercise Science Department close to the recruiting hospital. Participants: PwMS (N=33; aged 47.6±7.9 y). Interventions: Participants were recruited after participation in a randomized controlled exercise trial; all had been allocated to a 12-week exercise programme, comprising supervised and self-directed exercise sessions. Main outcome measure: Exercise perceptions and experiences before, during and after participation in the program. Results: Four themes emerged from the analysis: (1) the transition to inactivity; (2) lack of knowledge and confidence; (3) positive exercise experiences; (4) perspectives on exercise adherence. Conclusion: Lack of confidence and exercise knowledge, coupled with negative perceptions about physical capabilities after an MS diagnosis, are clear barriers to exercise participation in PwMS. These issues are not being adequately addressed as part of the healthcare pathway or in community settings. Perceptions of improved posture, ability to overcome everyday difficulties, acute mood enhancements during and after exercise and increased opportunities for social interaction were amongst the reported benefits of exercise participation. Despite the provision of a personally-tailored exercise plan and use of cognitive behavioural strategies, self-directed exercise continued to present challenges to PwMS and the importance of seeking cost-effective ways to maintain motivational support was implicit in participant responses.