Many nursing home residents are unoccupied and at risk for poor health outcomes because of inactivity. The purpose of this study was to identify characteristics of residents with dementia that predict engagement in activities when activities are implemented under ideal conditions. Data from a clinical trial that tested the efficacy of individually prescribed activities were used to address the study aim. Thirty subjects were videotaped daily for 12 days during 20-minute activity sessions. Measures of engagement (time on task and level of participation) were taken from these videotapes. Univariate logistic regression analyses indicated that cognitive status and physical function explained a significant amount of variance in engagement. Efforts to promote function may facilitate even greater benefits from prescribed activities by improving capacity for engagement.