The objective of this clinical trial was to determine the frequency of medical tests considered unnecessary in routine preoperative evaluation for cataract surgery. Unnecessary costs with these tests were also evaluated. For patients assigned to the selective testing group, it was requested that no preoperative testing be performed unless the patient presented a new or worsening medical problem warranting medical evaluation with testing. For patients assigned to the routine testing group, three tests were requested: a 12-lead electrocardiogram, complete blood count, and serum glucose level. The costs of tests considered unnecessary were calculated. The sample of 1,025 patients consisted of 512 assigned to the routine testing group and 513 to the selective testing group. Cumulative rate of medical events was similar in the two groups (p=0.923). The selective group underwent 60.7% fewer tests. The results suggest that selective preoperative testing in cataract surgery does not harm patients in terms of peri-operative clinical complications and also represents a significant cost reduction compared to routine testing.20303-10