In 1992 the known southern limit of Aedes albopictus in Florida was in Lee County. Through oviposition surveillance, the distribution of Ae. albopictus was determined, and its frequency relative to Aedes aegypti and colonization pattern of areas previously occupied by Ae. aegypti were examined in Lee County. The data collected in the first year of surveillance demonstrate the ability of Ae. albopictus to rapidly and preferentially colonize large expanses of rural southwest Florida. Urban and suburban areas of the county showed slower colonization rates. In suburban areas, Ae. albopictus became the dominant container-breeding mosquito species, whereas it did not become dominant in urban areas. During the study period, Ae. albopictus did not displace Ae. aegypti in urban or suburban habitats. The southern limit of Ae. albopictus moved a distance of 8.1 km (5 mi.) in 6 wk to the southern border of the county.