A 50-year-old Taiwanese woman was admitted for psychiatric inpatient treatment because of bipolar I disorder. The patient presented the symptoms of elevated mood, pressured speech, flight of ideas, grandiose delusion, and predominant aggressive violent behavior for 2 months despite treatment with lithium, 900 mg per day. She denied history of drug abuse or cardiovascular disease. Initial laboratory studies revealed normal ranges. The Young Mania Rating Scale (YMRS) total score was 49 on the first hospital day. However, treatment with lithium seemed to be ineffective, and the YMRS total score was 46 on the eighth hospital day. Following this condition, we added ECT three times per week for our patient. She also underwent cardiac, odontological, and neurological evaluations to identify any possible clinical conditions counterindicating ECT. Then, she received lithium combined with bilateral ECT at an electrical dose of 30% energy using the Thymatron DGx model IV. Surprisingly, the aggressive behavior subsided and the YMRS total score was improved to 7 after two sessions of ECT. The mean seizure duration, as assessed by clinical observation, was 26 seconds, whereas the total seizure duration was 52 seconds. The blood lithium level maintained 0.71 and 1.05 meq/liter. However, no prolonged seizures, postical delirium, or respiratory complications were noted.