We examined the relationships among Lepidopteran species richness and relative abundance, field and park size, and herbaceous plant richness and cover in parks of New York, NY. Lepidopteran populations and habitats were quantified from 1 June-30 September 2002 in fields of 8 New York City (NYC) parks. We observed 42 species of Lepidoptera, with park size, field size, and plant species richness positively related to Lepidopteran abundance and species richness. Several plant species received heavy use and appeared to be important to Lepidoptera in this urban environment, particularly butterfly-bush (Buddleia davidii), mugwort (Artemisia vulgaris), knapweed (Centaurea maculosa), and clover (Trifolium spp.).