We report two cases of methanol poisoning and evaluate the kinetics of methanol, ethanol, and formate. The first case was a 48-year-old man (case 1). His initial methanol level was 56.4 mg/dL and serum ethanol level was 2.4 mg/dL. Serum formate was not detected, and ethanol administration was initiated. However, methanol was eliminated slowly, and serum formate increased. His methanol and formate levels decreased rapidly following hemodialysis. He was discharged without any sequelae. The second case was a 35-year-old man (case 2). His serum methanol level was 400 mg/dL, and serum ethanol was not detected. His serum formate level was 13.4 mg/dL, and ethanol and activated folate were administered. He underwent hemodialysis immediately after diagnosis. Methanol and formate decreased rapidly, and he was discharged without any sequelae. Methanol and formate are eliminated slowly if ethanol is administered alone. We suggest that hemodialysis should be considered immediately after ethanol administration.