Background Acute care at home ("home hospital") compared to traditional hospital care has been shown to lower cost, utilization, and readmission and improve patient experience and physical activity. Despite these benefits, many patients decline to enroll in home hospital. Objective Describe predictors and reasons why patients decline home hospital. Design Mixed methods evaluation of a randomized controlled trial. Participants Patients in the emergency department who required admission and were accepted for home hospital by the home hospital attending, but ultimately declined to enroll. Intervention Home hospital care, including nurse and physician home visits, intravenous medications, remote monitoring, video communication, and point-of-care testing. Approach We conducted a thematic content analysis of verbatim reasons for decline. We performed bivariate comparisons then multivariable logistic regression to identify patient characteristics associated with declining participation. Key Results Two hundred forty-eight patients were eligible to enroll, and 157 (63%) declined enrollment. Patients who declined and enrolled were of similar age (median age, 74 vs 75 years old; p = 0.27), sex (32% vs 36% female; p = 0.49), and race/ethnicity (p = 0.26). In multivariable analysis, patients were significantly more likely to decline if they initially presented at the community hospital compared to the academic medical center (53% vs 42%; adjusted OR, 2.2 [95% CI, 1.2 to 4.2]) and if single (37% v 24%; adjusted OR, 2.5 [95% CI, 1.2 to 5.1]). We formulated 10 qualitative categories describing reasons patients ultimately declined. Many patients declined because they felt it was easier to remain in the hospital (20%) or felt safer in the hospital than in their home (20%). Conclusions Patients who declined to enroll in a home hospital intervention had similar sociodemographic characteristics as enrollees except partner status and declined most often for perceptions surrounding safety at home and the ease of remaining in the hospital.