To determinate the predictive value of preoperative glucose test of diabetic patients, with age above 40 years, for visual acuity outcome and clinical perioperative complications, in cataract surgery with local anesthesia, in an academical medical center. Type 2 diabetic patients, above 40 years of age, indicated for cataract surgery between February 10, 2000 and January 10, 2001, at the State University of Campinas, São Paulo, Brazil. All patients had a preoperative medical assessment by a physician one week before surgery, and were submitted to serum fasting glucose test and 12-lead electrocardiogram. There was no delay in the surgeries of patients with abnormal serum glucose test results, so, the result of the test alone was not a reason to cancel the surgery. According to the glucose test, the patients were assigned to one of two groups: Normal Glucose Test Group (60-115 mg/dL) or Abnormal Glucose Test Group (>115 mg/dL). Postoperative best-corrected visual acuity and clinical perioperative complications were recorded on a standardized form. The sample consisted of 193 patients. 67 (34.7%) had a serum glucose test within normal limits (normal glucose test group) and 126 (65.3%) outside normal limits (abnormal glucose test group). The mean result of the normal glucose test group was 98.5+/-17.3 mg/dL and 166.5+/-48.9 mg/dL for the abnormal glucose test group (p<0.001). We observed perioperative complications in 21 (10.7%) patients, all arterial hypertension cases; 7 (10.5%) of these in patients with normal glucose test result and 14 (11.1%) in patients with abnormal result (p<0.888). The postoperative best-corrected visual acuity was similar in both groups. There was no influence of the preoperative serum glucose level on perioperative clinical complications or visual acuity outcome.68213-7