Nine eligible papers were identified. The most common adherence measures were the proportion of participants completing exercise programs (ie, did not cease participation, four studies, range 65 to 86%), proportion of available sessions attended (five studies, range 58 to 77%) and average number of home exercise sessions completed per week (two studies, range 1.5 to 3 times per week). Adherence rates were generally higher in supervised programs. The person-level factors associated with better adherence included: demographic factors (higher socioeconomic status, living alone); health status (fewer health conditions, better self-rated health, taking fewer medications); physical factors (better physical abilities); and psychological factors (better cognitive ability, fewer depressive symptoms). Conclusion: Older people's adherence to exercise programs is most commonly measured with dropout and attendance rates and is associated with a range of program and personal factors.