The Nelson Environmental Study Area (NESA) is maintained by the University of Kansas for experimental research in ecology. Since 1983, benthic and emergent aquatic macroinvertebrates have been collected as part of several research projects. In this paper, we present the taxonomic composition and emergence phenologies of Chironomidae collected at NESA. Emergence traps, artificial substrate samplers, light traps and hand-picked specimens from D-nets yielded a total of 123 species, 41 of which are new records for Kansas. Chironominae was the most species rich subfamily with 79 species, while Tanypodinae and Orthocladiinae were represented by 25 and 19 species, respectively. Emergence phenologies from small, replicated, experimental ponds were determined by quantitative sampling in 1988 and 1989. In both years, many taxa showed patterns of seasonal emergence, being restricted to one of the three seasons sampled, while 9 (1988) and 12 (1989) taxa emerged over most or all of the sampling periods. Cladotanytarsus spp. and Psectrocladius vernalis were the most abundant taxa in 1988 and 1989, respectively. Chironomid distribution patterns at NESA and their relevance to patterns across the state are discussed. Annotations are provided for selected taxa and new records for the state are indicated.