BMX (an acronym for Bicycle Motocross) is a form of cycling on specially designed bicycles which usually have 18 to 24-inch wheels (the norm being the 20-inch wheel). The sport includes racing on earthen tracks, known as BMX racing, as well as the performance of tricks on the bikes, called Freestyle BMX.

Freestyle BMX(Bicycle Moto Cross) has grown to include five distinct disciplines. These are Street, Park, Vert, Dirt, and Flatland. These usually involve technical movements of the bike in different ways over varied terrain.

Recently, BMX racing's international governing body, Union Cycliste Internationale (UCI), began sponsoring the UCI BMX World Championships. In 2008, BMX racing will enter the Olympics for the first time in Beijing, China.