This article, utilizing U.S. Census data in 1980 and 1990, probes the relationship between immigration and urban sprawl. The preliminary findings reveal that population growth caused by immigration is not likely the major causal factor to urban sprawl. The lifestyle of native-borns is more prone to inducing urban sprawl, since native-borns have generated most of the growth in the number of households, owner-occupied housing, suburban residency, demand for new housing, and private automobile usage for work-trips. The article also shows that household behavior is a critical factor in causing urban sprawl. Household growth rather than population growth has a stronger causal linkage with urban sprawl. Future research, implementing microdata, is necessary to better disentangle the complex relationship.