In the Mario Kart series, Fireballs are used as special weapons. They could be either red or green, like Red Shells and Green Shells. In Super Mario Kart, Bowser would drop these items; touching them would make the driver spin out. Unlike other laid down items such as Banana Peels, however, they would move around a bit on the course, making them more hazardous. Fireballs reappeared in Mario Kart: Double Dash!!, where they are the special item of both Mario and Luigi. It can used by Petey Piranha and King Boo, too. Luigi use green fireballs, the other characters use red fireballs. When the special item is used, five fireballs will be launched into the racetrack, hitting other drivers and causing their karts to spin-out. These fireballs are capable of ricocheting off walls. However, after a short amount of time, the launched fireballs will fizzle out. In Mario Kart 7, the Fire Flower allows a player to throw fireballs at other drivers for a short period of time. These fireballs fizzle out quickly but retain the ability to ricochet off of walls. The Fire Flower returned in Mario Kart 8 and Mario Kart 8 Deluxe.

Fireballs may also be present in games as stage hazards. In both Double Dash and Wii, Mechanical Bowser appears on Bowser's Castle and will shoot fireballs in a straight line on the track, forcing drivers to either dodge or get hit. The artificial Bowser may switch left and right to cover both sides of the track. Large versions of fireballs are launched from the sky in Mario Kart DS's Desert Hills and Mario Kart Wii's Grumble Volcano and burn upon contact with the ground, spinning out any player who is careless enough to drive through them, just like them getting shook up by the POW Block item.