According to the Global Historical Database by the National Centers for Environmental Information, the oldest historical tsunami record in Central America is the earthquake tsunami that occurred in Mexico in 1537; however, this record is doubtful because this tsunami is reported by no authority outside Japan. Here, I examined earthquake and tsunami catalogs and found the source of this suspicious data. Imamura (1925) compiled the first part of the chronological table of major earthquakes in the world from the earthquake catalog of the world by Milne (1912). During this compilation, information on the tsunami caused by the 1531 Spain–Portugal earthquake was not copied. The chronological table was published almost annually until 1962; during this time the table was revised in 1958 by Kawasumi, who was the author in charge at the time. The remarks for the 1531 Spain–Portugal earthquake tsunami should have been added during the revision, but the text “tsunami existence” was erroneously added to the next entry for the 1537 Mexico earthquake. The source of the 1537 tsunami report was this miscopy.