This episode takes place in 3085.
The structure used as the arena was the only building remaining from the "Ape City" set of structures built on location for the original movie, also used on "Beneath the Planet of the Apes".
William Smith had guest-starred on a Mr. Lucky episode also titled "The Gladiators" (1960).
Production number of this episode is B-502.
This episode was used as the first half of the second compilation movie "The Forgotten City of the Planet of the Apes" released in 1980, paired with "The Legacy".