Objective To investigate the clinical and brain magnetic resonance imaging (MRI) features of hypoglycemic encephalopathy (HE).Methods The clinical features and brain MRI data of 69 patients with hypoglycemic coma (HC) were analyzed retrospectively.Results The causative factors of HC were complex and usually included poor appetite, diarrhea, upper respiratory tract infection, and improper use of hypoglycemic drugs. These patients had various clinical manifestations, including disturbance of consciousness, hemiplegia, tetraplegia, gaze palsy, and Babinski sign (seen in most cases). Eighteen cases were found to have abnormal hyperintensity on DWI of the brain, mainly involving the hippocampus, basal ganglia, cerebral cortex, and subcortical white matter, and most of them had bilateral, symmetrical lesions. The patients without brain damage on MRI had a significantly higher percentage of individuals with a good outcome than those with brain damage on MRI, (94.12% vs 22.22%, P=0.0011), according to the follow-up conducted at 3 months after treatment. Ten of the patients with brain damage on MRI had a poor outcome, and 9(90%) of them had cortical damage.Conclusions HE has no specific clinical manifestations, and hypoglycemia should be considered for patients with coma, especially the elderly. Improper use of hypoglycemic drugs is the main trigger for HE. Brain MRI is superior to brain CT, and the DWI sequence is of great significance for testing the brain damage caused by hypoglycemia. The patients with cortical damage have a poor prognosis.