Although overestimation of blood glucose (BG) by certain glucometers in peritoneal dialysis (PD) patients has been reported, awareness of this problem by healthcare providers of multiple disciplines and different specialties is probably insufficient. This is a case series of four patients who had severe symptomatic hypoglycemia and normal BG by point-of-care glucometer at a tertiary care center from December 2007 to September 2008. We report four insulin-treated diabetic patients (age = 58.2 ± 16.2 years, 3 men and 1 woman) on PD, who had acute decrease in level of consciousness in the emergency department (n = 1) and the hospital ward (n = 3). While they had their symptoms, they all had normal BG measured by the Accuchek glucometer (7.1 ± 3.3 mmol/L); nonetheless, simultaneous or near-simultaneous laboratory-measured BG levels were very low (2.0 ± 1.3 mmol/L). The mean difference in BG was 5.8 mmol/L (12 simultaneous or near-simultaneous measurements). Three patients had icodextrin-based PD in the night before symptomatic hypoglycemia. The first two patients, whose treatment for hypoglycemia was delayed, remained comatose and died later. The latter two patients were promptly treated with intravenous dextrose and did not have any neurologic sequelae. One of them died later from multiple organ failure. Over-estimation of BG in peritoneal dialysis patients by certain point-of-care glucometers is a serious problem and can be fatal. Increased awareness of this problem for all healthcare providers and use of appropriate glucometers are required.