Early diagnosis of ethylene glycol poisoning is crucial in order to prevent morbidity and mortality. However, diagnosis can sometimes be delayed because of the false elevation of lactate in some chemistry analyzers as a result of the interference of glycolate, a metabolite of ethylene glycol. We present a case of ethylene glycol poisoning presenting with a falsely elevated lactate level on a blood gas analyzer in the emergency department. Given the fact that nowadays there is a marked increase in use of point-of-care analyzers, one should be aware of possible false readings since they use different methods of measuring compared with clinical chemistry analyzers. On the other hand, measuring a lactate gap using two different technologies, only one of which is sensitive to glycolate, could be a clinically efficient way to make the diagnosis of advanced ethylene glycol poisoning in the emergency department or other critical care setting.