During 1978 and 1979, mosquito larvae were collected in Delaware County, Indiana in an effort to detect any changes in the mosquito fauna since an earlier study by Siverly (1966). The total number of species identified in the current study is 24. Four new county records, Aedes hendersoni, Culex tarsalis, Orthopodomyia alba, and Psorophora howardii are reported. By comparing qualitative productivity of selected mosquito habitats it does not appear that the mosquito fauna of Delaware County has changed significantly in the interim since Siverly's study.