Methadone Poisoning is one of the most common drug Poisonings, especially in children, which can cause dangerous and sometimes fatal complications in children. The patient in question is an 8-month-old infant who was accidentally poisoned with methadone syrup and was taken to the hospital by her parents with severe drowsiness and decreased level of consciousness. After appropriate and rapid initial diagnostic and therapeutic measures, she was fortunately discharged in good general condition and without complications, and with necessary recommendations. Given that methadone is used for addiction treatment and is often stored improperly at home, it is recommended that this medication be stored securely and kept out of the reach of children. Additionally, if possible, it should be administered exclusively in addiction treatment centers rather than at home.