This study conducts an operational analysis of horizontal evacuation in a hospital using a crowd density model to simulate patient evacuation. The proposed discrete-event simulation model considers three types of patients assigned with specific moving speed and areas from which to evacuate; the moving speed also varied according to the area's crowd density. We evaluated the effect of the ratio and transfer priority for each patient type on evacuation time in the ward. During night shifts, the evacuation time increased with the ratio of type 1 patients transferred by two nurses with sheets or blankets. The results showed only slight differences in evacuation times when transfer priority changed between type 1 and type 2 patients. The hospital required only one additional staff member to shorten the evacuation time during night shifts.