Objectives: To identify factors that are associated with older patients' engagement in exercise in the 6 months after hospital discharge. Design: A prospective observational study using qualitative and quantitative evaluation. Setting: Follow-up of hospital patients in their home setting after discharge from a metropolitan general hospital. Participants: Participants (N=343) were older patients (mean age ± SD, 79.4±8.5y) discharged from medical, surgical, and rehabilitation wards and followed up for 6 months after discharge. Interventions: Not applicable. Main Outcome Measures: Self-perceived awareness and risk of falls measured at discharge with a survey that addressed elements of the Health Belief Model. Engagement and self-reported barriers to engagement in exercise measured at 6 months after discharge using a telephone survey. Results: Six months after discharge, 305 participants remained in the study, of whom 109 (35.7%) were engaging in a structured exercise program. Multivariable logistic regression analysis demonstrated participants were more likely to be engaging in exercise if they perceived they were at risk of serious injury from a fall (odds ratio [OR] =.61; 95% confidence interval [CI],.48.78; P<.001), if exercise was recommended by the hospital physiotherapist (OR=1.93; 95% CI, 1.033.59; P=.04), and if they lived with a partner (OR=1.97; 95% CI, 1.183.28; P=.009). Barriers to exercise identified by 168 participants (55%) included low self-efficacy, low motivation, medical problems such as pain, and impediments to program delivery. Conclusions: Older patients have low levels of engagement in exercise after hospital discharge. Researchers should design exercise programs that address identified barriers and facilitators, and provide education to enhance motivation and self-efficacy to exercise in this population.