Street racing is a form of auto racing taking place on public roads, either during normal traffic or during empty hours of traffic, often within the city area. It is the only form of illegal auto racing since all traffic regulations forbid the type of driving involved in such racing. Virtually all street races are hunted down by police since mandatory traffic rules such as maximum speed limit and limits on recklessness are most likely not obeyed.

Most common form of street racing is a drag race of modified stock cars happening late nights on a partially, but certainly illegally closed straight public road with a very low traffic. The driving forces behind illegal street races are many, lack of a nearby drag strip, the temptation of illegality of such a race, which could be interrupted by a police squad any time, or just the similarity to a day to day situations at the traffic lights. Streetracing is also a growing business with streetracers being influental consumers of aftermarket tuning parts. It is even possible to find professional streetracers in these days, however contradicting it may sound. Nonetheless streetracing should be considered as an integral part of the underground portion of the urban lifestyle, well since the mid of the 20th century.

In some places there have been legal street races (sometimes called "blackrace"). This is not the same as road racing and it's strictly an amateur sport with road legal vehicles. Usually the races are done on a closed road and run on time and not against another vehicle. It should be noted that illegal street racing is rare where drag strips are within a reasonable driving distance.