I noted with interest the report on "Methemoglobinemia Due to Benzocaine" (Pediatrics, 20:915, 1957), apparently caused by an ointment containing benzocaine. I had expected that sooner or later such a case would be reported. Dr. Wolff referred to a case I reported previously: "Methemoglobinemia in an Infant —Associated with Application of a Tar-Benzocaine Ointment" (J. Pediat., 47:22, 1955). At the time this was reported I was uncertain as to whether the 2½% tar or the 5% benzocaine in the ointment was the toxic factor, and could find no case of methemoglobinemia caused by either substance in ointment or otherwise.