The abundance and location of eggs of Aedes aegypti were evaluated through inspection of 24 Tucson homes during the winter of 1998-99 to assess the potential of the mosquitoes to overwinter in this area. Eggs were found either indoors or outdoors in 46% of residences surveyed. After immersion in water, about 23% of eggs found indoors hatched, and about 5% of eggs found outdoors hatched.