Despite its narrow therapeutic index, lithium remains widely used as a mood stabilizer for the treatment of bipolar disease. The cardiac side-effects of lithium have been well documented, and may induce non-specific T-wave flattening, prolonged QT interval, sinus node dysfunction and also ventricular tachycardia and ventricular fibrillation. We report the case of a 61-year-old male patient diagnosed with bipolar disorder who developed life-threatening cardiac manifestations secondary to severe lithium poisoning. Although hemodialysis was performed and the arrhythmias were adequately treated, the patient died on the sixth day after hospital admission due hemorrhagic complications after tracheostomy.