This study aimed to examine the effects of semi-immersive virtual reality (VR)-based exercise on the quality of life of older adults. It used a randomized controlled trial design. Older adults (mean age: 72.16 ± 4.9 years) were randomly assigned to experimental (n = 48) and control (n = 50) groups. The experimental group engaged in semi-immersive VR exercise for 75-90 min, twice a week, for 12 weeks and partook in no other intervention between the end of the exercise intervention and follow-up. Control group members did not participate in any similar program during the intervention or follow-up periods. Both groups completed three assessments: at baseline (pre-test), post-intervention (post-test), and 3 months later (follow-up). Quality of life was assessed using the World Health Organization Quality of Life Instrument-Older Adults Module. Generalized estimating equation analyses indicated that the experimental group exhibited significant post-intervention improvements in quality of life in terms of sensory ability, autonomy, social participation/isolation, death and dying domain, and overall quality of life scores. However, none of these significant effects were maintained 3 months after exercise intervention cessation. Semi-immersive VR exercise may be a feasible strategy toward enhancing the quality of life of older adults. However, the participants' quality of life was not maintained upon exercise cessation, indicating that older adults need to be encouraged to exercise regularly to maintain a good quality of life. VR may need to be combined with other modes of intervention in the future to facilitate long-term quality-of-life improvement in older adults.