Objective: To describe glioblastoma patients’ and carers’ perspectives of participating in a tailored exercise intervention during chemoradiotherapy. Methods: A pilot study was conducted to evaluate if exercise was a feasible and safe therapy in patients with glioblastoma undergoing chemoradiotherapy. Patients received a supervised exercise intervention involving an individualised prescription of moderate-intensity aerobic and resistance exercise twice weekly, performed at the hospital when they attended for treatment. Semi-structured interviews were conducted with participants and their carers. Recordings were analysed using thematic analysis. Results: 19 patients and 15 carers participated. Benefits and challenges of participating in the exercise intervention were described. Benefits included an individually tailored exercise program, improvements in health, regaining a sense of control, interacting with people, keeping active and benefits for carers. Challenges included managing symptoms associated with diagnosis and treatment, juggling treatment and exercise, and difficulties engaging in the program. Conclusion: Patients and carers expressed positive perceptions and experiences of participating in exercise during chemoradiotherapy; however, some challenges were experienced. These results support the quantitative pilot study which demonstrated that supervised exercise is feasible, safe and well tolerated by patients receiving chemoradiotherapy for glioblastoma. Randomised controlled trials now need to be conducted with this population.