Carbon dioxide-baited tick traps were used to collect larval Ixodes dammini Spielman, Clifford, Piesman, and Corwin in the summer of 1983 at 5 sites in Westchester County, New York. Larval collections ranged from 0 at one site to 712 at another during 1 week sampling periods between 26 July and 26 August. There was no significant difference between morning and evening collections, indicating that larvae are constantly active. No correlation was found between the number of larvae on tick traps and the number of larvae found on white-footed mice, Peromyscus leucopus. C02-baited tick traps are effective in sampling immature I. dammini and may be useful in determining human risk for Lyme disease.