The infant was found unresponsive in bed, face down on a pillow, and emergency efforts to resuscitate him were unsuccessful. The official cause of death was attributed to sudden infant death syndrome (SIDS); however, a toxicological evaluation revealed a concentration of 3.48 mg/L of benzocaine, a widely used local anesthetic found in many over-the-counter medications. Benzocaine is a relatively safe local anesthetic, but there are two recognized adverse reactions, allergic sensitization and methemoglobinemia. Methemoglobin is hemoglobin with the iron oxidized to the ferric state (rather than the reduced ferrous state), making it incapable of reversibly binding oxygen. Death may result from methemoglobinemia if medical intervention is delayed. The corner's investigation of the source of the benzocaine in the infant found that he was treated with Zenith Goldline Allergen Ear Drops, which contained 0.25 percent w/v benzocaine and 5.4 percent w/v antipyrine. A caregiver admitted that on the day before the child's death he had been treated with three times the prescribed dose. Methemoglobin concentrations in postmortem cases are frequently elevated, however, and should be interpreted with caution. Still, in the current case, the unknown significance of the benzocaine and the circumstances of the case raise questions about attributing the child's death to SIDS. 1 table and 11 references