The Kaio-ken Kamehameha is a combination of the Kaio-ken technique and the Kamehameha Wave, used by Goku. Goku transforms into his Kaio-ken form and uses the Kamehameha, inflicting multiple damage depending on what Kaio-ken level he is using for the attack. The only known Kaio-ken levels he used for the attack are Kaio-ken x3, Kaio-ken x4, and Kaio-ken x20.
After being battered around by Goku's Kaio-ken x3 attack, Vegeta ended up losing his temper. The Saiyan prince then flew up in the air and launched his Galick Gun, intent on destroying Goku along with the Earth. Out of fear of letting the blast hit the Earth, Goku used the Kaio-Ken x3 Kamehameha to repel the Galick Gun. Seeing how both attacks were evenly matched, Goku used the Kaioken x4 Kamehameha, surging through the Galick Gun and blasting Vegeta into the sky. However, his body was left very exhausted and weakened from having used so much power.
During the fight with Frieza, Goku gets thrown underwater by the tyrant, who attempts to drown him. However, after seeing a vision of his friends and family being murdered, Goku regains courage and raises his Kaio-ken to x20, the highest Kaio-ken level. Goku then beats around Frieza and fires a gigantic Kaio-ken Kamehameha the tyrant, damaging him slightly. The blast was named Kaiken x20 Kamehameha in Dragon Ball Z: Budokai Tenkaichi 3.
In Dragon Ball Z : Supersonic Warriors 2, Goku's ultimate attack is Kaio-ken Times 20.
Goku used the Kaio-ken x3 attack against Dr. Wheelo (which broke off one of Dr. Wheelo's claws) and then launched a Kaio-Ken Kamehameha against the giant robotic scientist. The blast destroyed Wheelo's lab fortress and sent Dr. Wheelo into outer space.Cooler in his final form, Goku used the Kaio-ken x20 Kamehameha against the tyrant. However, unlike his brother Frieza who was damaged by the attack, Cooler simply surged through the blast and attacked the surprised Goku.