Objective: We evaluated patients’ degree of understanding of the effects and adverse drug reactions of SGLT2 inhibitors.Methods: We targeted 26 patients who were administered SGLT2 inhibitors during hospitalizations between April 2017 and March 2018. The survey was conducted by interviewing the patients using a questionnaire.Results: In total, 14 patients (53. 8%) were able to explain the term “efficacy.” Although 6 patients (23. 1%) understood “dehydration,” there was little understanding of “urinary tract infection” (7.7%) and “rash/erythema” (2 and 0 patients, respectively). In addition, we confirmed the details of the descriptions of adverse reactions caused by SGLT2 inhibitors with pharmacists, and found that 13 patients (50.0%) clearly received an explanation of “dehydration,” only 3 patients received an explanation of “urinary tract infection” (11.5%), and none of them comprehended “rash/erythema.” Overall, the patients’ awareness of the adverse drug reactions of SGLT2 inhibitors was low.Conclusion: Unlike common drugs for diabetes, SGLT2 inhibitors have been attracting attention as protective agents of the heart and kidneys. Therefore, it is expected that prescriptions for SGLT2 will increase in the future. Pharmacists need to explain the effects and adverse drug reactions of SGLT2 inhibitors to the patients as well as make the patients understand the pharmacological mechanisms of action of SGLT2 inhibitors.