Yul Brynner did not want to return to the role of Chris, so the role was taken by George Kennedy, then at a height of popularity after winning his Academy Award for Cool Hand Luke (1967).
Despite bearing no resemblance to Yul Brynner, George Kennedy took over the role of Chris Adams, played by Brynner in the first two films. Even Adams' trademark dark clothing is gone. What remains is the steel resolve, and affinity for cigars.
Fernando Rey is the only actor besides Yul Brynner to appear in two Magnificent Seven films. He played a priest in Return of the Seven (1966) and the captured leader of the revolutionaries in this movie.
Executive Producer Walter Mirisch felt that in the unpredictable market of filmgoers, there was safety in familiar material.