Two hundred patients undergoing vitreoretinal surgery were prospectively studied to determine the postoperative hospitalization requirements and to analyze preoperative and intraoperative factors that influence the need for inpatient care. Fifty-two percent of the patients had postoperative events that were best treated in an inpatient setting. Forty-four patients (22%) had pain requiring intramuscular injections five or more hours following surgery, 35 patients (18%) had nausea requiring intramuscular medications five or more hours following surgery, 30 patients (15%) required physician consultation for medical illness five hours or more following surgery, and 41 patients (20%) required more than one postoperative day of hospitalization because of ocular abnormalities. We concluded that although vitreoretinal surgery can sometimes be performed on an ambulatory basis, most cases require hospitalization for optimum care.