BACKGROUND AND PURPOSE: Exercise interventions can improve physical recovery and reduce falls in older adults following hospitalization. The aim of the study was to identify factors associated with exercise engagement after hospital discharge. METHODS: This study was a secondary analysis of data collected as part of a randomized controlled trial. Participants were 60 years and older, discharged from 3 rehabilitation hospitals in Australia, and followed for 6 months after discharge. The primary outcome was level of engagement in exercise after discharge, measured using setting, type, frequency, and time. A secondary outcome was self-efficacy for exercise at 6-month follow-up. Data were gathered at baseline in hospital and at 6 months after discharge by telephone using structured surveys. Associations between exercise and participant characteristics were evaluated using logistic regression models. RESULTS AND DISCUSSION: Participants' (n = 292) mean age was 78 (SD 8) years and 63% were female. There were 146 (50%) who exercised after hospitalization for a median (interquartile range) time of 60 (60-75) minutes per week. Characteristics that were significantly associated with post-discharge engagement in exercise were having higher levels of functional ability at discharge (adjusted odds ratio [AOR] 1.2, 95% CI 1.0, 1.4), living with a partner (AOR 2.9, 95% CI 1.7, 4.9), and engagement in exercise prior to hospital admission (AOR 1.7, 95% CI 1.0, 2.8). The mean self-efficacy for exercise score at 6 months post-discharge was 58.5/90 (SD 24.5). Characteristics that were significantly predictive of a higher mean self-efficacy score at 6 months after hospitalization were having a college or university education (adjusted β-coefficient [Adj β] 11.5, 95% CI 3.8, 19.0), exercise prior to hospital admission (Adj β 12.3, 95% CI 5.1, 19.5), living with a partner at discharge (Adj β 14.5, 95% CI 7.1, 21.9), and higher functional ability at discharge (Adj β 4.0, 95% CI 1.9, 6.1). CONCLUSION: Older adults have low levels of engagement in exercise that might impact their recovery after hospitalization. During exercise prescription, clinicians should prioritize older adults who live alone, who have lower functional ability, and no previous habit of exercising.