Kaio-ken Finish (界王拳フィニッシュ) is a rush attack used by Goku while using his Kaio-ken technique. First, Goku charges at the opponent and kicks them up into the air. Then, he flies up after the opponent and double axe-handle punches them down to the ground. Next, he powers up to his Kaio-ken technique as he charges down at the opponent and double-punches them in their back. Finally, Goku quickly lands on the ground and catches the opponent on their back before throwing them onto the ground, inflicting a great deal of damage.
Goku used this attack to defeat Nappa. Frustrated that he was unable to defeat Goku, Nappa decided to take his anger out on Gohan and Krillin. Nappa charged down to the ground where the frightened Gohan and Krillin were and prepared to kill them with the Break Cannon (a mouth blast), with Goku in pursuit. Realizing he was not fast enough to stop Nappa, Goku activated his Kaio-ken technique and attacked Nappa with the Kaio-ken Finish, breaking the Saiyan's back and saving Gohan and Krillin. Goku stated that Nappa's injuries were so severe that he was unable to fight ever again.
Goku later used a similar attack against Burter on Planet Namek, knocking out the Ginyu Force member and allowing Vegeta to kill him, much to Goku's dismay. He also used it to kill Kishime in the movie Dragon Ball Z: The World's Strongest.
Kaio-ken Finish was named in Dragon Ball: Raging Blast, and is also one of Goku's Super Attacks in his base form. It was also one of Goku's Blast 2 attacks in Dragon Ball Z: Budokai Tenkaichi and Dragon Ball Z: Budokai Tenkaichi 2, under the name Kaio-ken Attack.