Aim : Less frequent exercise intervention may protect frail elderly persons from physical and psychological burdens and help minimize expenditure on human and economic resources by local governments. However, very few studies have explored the effects of the frequency of such intervention, which aims to help frail elderly persons become accustomed to voluntary exercise. Furthermore, the number of studies of functional fitness, visual attention, and quality of life (QOL) has been limited. To address this research gap, the present study compared the effects of less frequent and more frequent exercise intervention on exercise adherence, functional fitness, visual attention, and QOL. Methods : Thirty-nine extremely frail adults participated in this study. Depending on the distance between the intervention facilities and the participants' homes, the participants were assigned to either a weekly session group (N=14; higher frequency: HF) or a fortnightly session group (N=25; lower frequent: LF). Participants in both groups attended 90-minute sessions comprising daily home exercises and behavioral management over 3 months. They were also asked to maintain an exercise log. Adherence to home exercise, functional fitness, visual attention, and QOL of the two groups were then compared. Results : During the 3-month intervention period, 2 participants in the LF group and 3 in the HF group dropped out. At the end of the intervention period, no significant inter-group differences were found in either session attendance or adherence to home exercises. ANOVA revealed significant time effects on functional fitness (tandem standing balance, standing and sitting 5 times in quick succession, sitting and reaching out) and QOL (bodily pain, general health, vitality, social functioning, role (emotional), mental health). A significant group-by-time interaction was found in QOL (social functioning), indicating that the HF group improved to a greater degree than the LF group, although the baseline in the HF group was significantly lower. For visual attention, neither a significant time effect nor interaction was found. Conclusion : Fortnightly intervention that involves motivating a frail elderly individual to exercise at home can help ensure that he or she adheres to home exercises and improves functional fitness and QOL. Similar effects are observed for weekly interventions, which might be required for frail elderly persons whose social functioning needs to be improved.