Case presentation In this case, we are presenting 26-year-old young patients, who took 60-gram metformin plus 900 mg pioglitazone, presenting with abdominal pain, nausea, confusion, and lethargy. And lactic acidosis was treated with continuous hemodialysis >15 hours. Our aim, in this case, is to highlight the importance of continuous hemodialysis in the treatment of metformin poisoning. Discussion Metformin is an oral antidiabetic drug which is used as a first line treatment in the treatment of DM. Metformin poisoning is a rare condition seen by clinicians. One of the severe side effects of metformin poisoning is lactic acidosis and it can be fatal without on-time treatment due to acidosis-related complications. Conclusion Metformin toxication is a rare condition seen in clinical practice. Metformin associated lactic acidosis is one of the expected complication. The continous dialysis can be effective to treat the lactic acidosis caused by metformin toxication. What’s already known about this topic? Lactic acidosis might be caused by metformin toxicity. Without on-time treatment for metformin toxicity, it can cause life-threatening condition. What does this article add? The treatment of hemodialysis, especially continous hemodialysis, might be beneficial to treat the patients with metformin toxicity. Key words: Metformin Toxicity, Dialysis, Lactic acidosis