Los Angeles has a long-standing reputation for urban sprawl, however, this reputation is not true. As of the 2000 Census, the Los Angeles, Long Beach, Santa Ana urban area had a residential density of more than 7,000 people per square mile, covering 1,600 square miles, making it the most densely-populated urbanized area in the United States. In comparison, the New York, Newark urban area boasted a population density of over 5,300 people per square mile, over 3,300 square miles.

The popular misconception of Los Angeles as a sprawling city might originate in the area's decentralized nature. Rather than being concentrated in a single downtown area, the region's major cultural, commercial, residential, political and industrial locations are dispersed over an intricate, intra-connected network. Although the overall density of the city of Los Angeles is small compared to some other large American cities, the noted figure is deceiving in part because the region includes largely uninhabited areas.

The residential density of the central area was more than 13,500 per square mile in 2000. Within its urbanized areas, Los Angeles is noted for small lot sizes, small vacancy rates, and general dearth of huge exurban spreads. In inner areas, it is not uncommon for people to share rooms or rent their living room to strangers. However, residential structures tend to be of very modest height compared to other very large cities in part because of strict earthquake building codes which escalate costs. Los Angeles became a major city just as the Pacific Railway dispersed the population to lesser cities. During the first decades of this century, the region was formed into a network of fairly dense but separated cities linked by rail. The ascendence of the automobile assisted in filling the spaces between these commuter cities with lower-density settlements.

The Los Angeles region continues to develop, mostly on the edges where new, less expensive, undeveloped areas are being sought. In such areas, the number of residents as well as home prices have exploded.