Topical anesthetics are commonly used in emergency departments. One of the side effects can be methemoglobinemia if not appropriately used. We present a case of a six-week-old baby who developed methemoglobinemia with levels of 30.6% after prolonged (15 hours) application of Eutectic Mixture of Local Anesthetics (EMLA) cream. The cream was applied for spontaneous drainage of a perianal abscess. The patient received IV methylene blue with a resolution of methemoglobinemia.