Background: Diabetic ketoacidosis (DKA) is the most common acute hyperglycemic complication of diabetes. According to a recent report DKA affects approximately 8 per 1000 diabetics annually. It is associated with significant morbidity and mortality, with a worldwide mortality rate of 2-10%. Objective: The aim of the work was to assessment of QTc interval prolongation among patients with DKA. Patients and Methods: This prospective observational cohort study included 100 patients who were diagnosed with DKA. The mean age of patients was 37.29±11.63 years, and 53% of them were males. All patients were subjected to detailed history taking, full clinical examination, laboratory investigations and 12-lead ECG. Results: Frequency of Prolonged QTmaxc amongst studied patients was 59%. Mean QTmaxc declined significantly after treatment to be 414.6±44.1ms compared to 482.45±63.56ms before treatment with p