Ovitraps were used to determine the distribution of Aedes triseriatus among forty-eight 1.2 km2 quadrants in urban South Bend and Mishawaka, Indiana. Oviposition paddles from 96 ovitraps were collected for 13 weeks from June to September, 1986. A total of 82,974 eggs was collected. Eggs were present in each quadrant at least once and were found in most quadrants on 6 or more collection dates. Ninety-two percent of the ovitraps were positive at least once, indicating ubiquitous distribution throughout the urban area. The eggs collected were 80-90% Ae. triseriatus, the remainder being Ae. Hendersoni. Effectiveness of large (3,100 ml) and small (350 ml) ovitraps was compared. The large ovitraps exceeded the small by 319% for eggs/positive ovitrap and 486% in numbers of positive ovitraps.