Lamivudine and adefovir are medications used to treat hepatitis B. We observed the occurrence of tinnitus after administering lamivudine and adefovir to a 49-year-old hepatitis B patient for two months. The patient had no comorbidities and no history of ear diseases, including tinnitus, and was not taking any other medications. In general, neither lamivudine nor adefovir are known to induce tinnitus as an adverse reaction. A literature search revealed that this is the first case in which tinnitus occurred after lamivudine and adefovir were administered to a hepatitis B patient. Therefore, we believe that this case is clinically valuable and decided to report it.