Methemoglobinemia is an altered state of hemoglobin by auto-oxidation resulting in impaired oxygen delivery to tissues. Methemoglobinemia can be congenital, but the acquired form is the most common, often caused by various drugs and toxins. Methylene blue is the most effective antidote for acquired methemoglobinemia. When methylene blue is not available, alternative treatments such as ascorbic acid, cimetidine, and hyperbaric oxygen may be helpful. In this article, we report a case of methemoglobinemia due to intoxication following voluntary ingestion of 50 tablets of dapsone for the purpose of suicide in a young child of 10 years.