Objective: The purpose of this study was to analyze the risk factors of hypoglycemia that occurs in hospitalized diabetic patients. Methods: The study's subjects were diabetic patients hospitalized in the division of endocrinology at Hospital A between January and December, 2013. Based on the records during hospitalization, the subjects were divided into a hypoglycemia group consisting of those with a minimal blood sugar level of below 70 mg/dL and a non-hypoglycemia group consisting of those with a minimal blood sugar level of 71 mg/dL or above. They were analyzed using the t-test, chi-square test, and multiple logistic regression analysis with SPSS version 21.0. Results: 83 out of 274 subjects experienced hypoglycemia at least once, and the two groups did not show statistically significant differences in gender, age, BMI, and the level of education. Risk factors were analyzed by dividing them into general characteristics, diabetes-related characteristics, characteristics related to diabetic complications, and characteristics related to other diseases. Finally, gender, smoking, education, and diabetic nephropathy were derived as risk factors for the occurrence of hypoglycemia. Conclusion: Women were 2.77 times more likely to experience hypoglycemia than men (P < .05), and smokers were 6.46 times more likely to experience hypoglycemia than nonsmokers (P < .001). Those with middle school or less education were 2.54 times more likely to experience hypoglycemia than those with at least high school education (P < .05). Among diabetic complications, those with diabetic nephropathy were 3.02 times more likely to experience hypoglycemia than those without the complication (P < .05). When nursing diabetic patients, repetitive education and continuous management may be required by setting goals for the control of blood sugar and taking separate approaches according to individuals based on risk factors that are highly likely to cause hypoglycemia.