A technique where chakra kneaded inside the body is converted into fire and expelled from the mouth, either as a massive sphere or as a continuous flame-thrower. The released flames will engulf their target, and is capable of leaving a crater in the ground's surface. The scope of this attack is altered by controlling the volume of chakra that is mustered.
- According to Kakashi Hatake, this technique was originally created by the Uchiha clan, becoming one of their favoured moves at which they became very adept.
- The characters for Fireball (火球) also means a "bolide", a "comet", and a "shooting star".
- In the manga, this technique is portrayed to be unique to the Uchiha clan. The anime, however, has portrayed it as a common Fire Release technique used by several non-Uchiha.
- During his battle with the Kazekage Rescue Team, Itachi was seen using the following hand seals to perform this technique: Boar, Horse, and Tiger.