Barrel racing, is a rodeo event that features a horse and one rider, running a cloverleaf pattern around three barrels in a triangular arrangement. The rider may decide on taking either the left or right barrel first, though it is often determined by the lead that the horse does best on.

The best barrel racers pocket the barrels as they come around them. Pocketing is defined as leaving a 3-6 foot gap between the horse and the barrel. The distance between the barrel and barrel horse varies from rider to rider, the gap tending to be more narrow with higher level barrel racers.

The cowgirl or cowboy (though barrel racing is traditionally a women's event, at the non-professional level many men also compete) will take a running start on his/her horse and ride towards the first barrel. At the first barrel, a rider should come at a slight angle. Its much harder on the horse if you come at the barrel straight on. They must make a complete turn around the barrel then race toward the second barrel. At the second barrel, they will again make a complete turn, which means they will make the turn in the opposite direction as the first barrel then race toward the third barrel. At the third barrel they will again make a complete loop in the same direction as the second barrel and then run back across the starting line which also is the finish line.

The racer may go to the right barrel first and turn it to the right and the second and third barrel to the left, or he/she can choose to go to the left barrel first in the triangular shaped pattern and turn it to the left and the other two to the right. The choice of which barrel to go to first is usually made by the racer based on the specific abilities of his/her horse and if they turn better to the right or to the left. The racers will pass through an electronic timer entering and leaving the barrel pattern and the elapsed time is the time for the event. However, if the racer tips a barrel over, he/she will be penalized with an extra five seconds being added to the time and in this competition where thousandths of seconds make the difference between first and second place, the extra five seconds will entirely take the racer out of the competition.

Since going wide around a barrel is slower, a delicate balance of speed and control must be made to achieve the fastest times. The time of the event is affected by the size of the arena in which the event is held and the distance between each barrel relative to the others and the time line. The stardard barrel pattern looks like an isosceles triangle with a base of 90 feet and sides each of 105 feet. The distance from the first barrel to the time line is 60 feet. These distances can be adjusted to fit the size of the arena in which the event is held, but the distance between the corner barrels and the top barrel must be equal.

A cowboy hat is part of the dress code for the event; if the riders hat falls off during a race, a rider will be fined $10-$25. This fine is unique to barrel-racing, though it is falling out of favor in non-professional competitions. The western shirt, jeans, cowboy boots, and western belt (usually with a prize buckle the competitor has won and also not required in the dress code) complete the dress-code of the barrel racing event.

The sport is governed by several bodies. The Women's Professional Rodeo Association (WPRA) governs on the professional level and several amateur associations exist, including the National Barrel Horse Association (NBHA).