It was contested by seven national teams playing twelve games each from September 14 through October 6 in Havana.

Cuba won its second, and second consecutive, Amateur World Series title.

Though only three of the fourteen teams that had been invited to the second Amateur World Series in Havana managed to attend the previous year, many of them participated in the 1940 edition, leading to a robust field of seven teams.

Mexico, Venezuela, and Puerto Rico all made their debuts at the Amateur World Series, as did Hawaii (which at the time was a U.S. territory), becoming the first team from Oceania to participate.

However, all of those nations had previously participated in regional competitions; Mexico at the 1926 Central American and Caribbean Games, Venezuela and Puerto Rico at the 1938 Central American and Caribbean Games, and Hawaii at the tri-national tournament held in Paris during the 1937 World's Exhibition.