Alternate versions

Shogun Assassin is actually an amalgam of two 1972 films titled Lone Wolf and Cub: Sword of Vengeance (1972) ("Lone Wolf and Cub: Sword of Vengeance") and Lone Wolf and Cub: Baby Cart at the River Styx (1972) (Lone Wolf and Cub: Baby Cart at the River Styx"). The producer decided to join the best bits of these two films (using around 10 minutes of the first film as a pre-credits flashback sequence to introduce the characters) and create "Shogun Assassin". The English-language dubbing included voice-over narration, ostensibly spoken by the child Daigoro.

Although often mentioned among video nasty titles the film was never officially listed among the 72 films originally targeted by the DPP. The original UK cinema version was cut by the BBFC to edit shots of heads being sliced with swords and closeups of clawed faces during the ship fight, and the 1992 Vipco video featured a pre-cut print which was also missing shots from the mirror blinding scene. The 1999 release featured the full uncut version.