Although tachinids are one of the most diverse families of Diptera (Irwin et al. 2003) and represent the largest group of non-hymenopteran parasitoids (Belshaw 1994), the ecology of most species in the family is poorly known. Most of the studies that have focused on tachinids are related to taxonomic descriptions. Currently, our knowledge is very limited in terms of the diversity and distribution of populations across time and space, especially in the Nearctic and Neotropical Regions (Stireman 2008). There have been a number of recent studies focused on diversity and temporal distributions of tachinids in the Palaearctic Region such as Ford and Shaw (1991, 2000), Avci and Kara (2002) and Richter (2005), but there are relatively few similar studies for specific areas of the Nearctic Region (though see O’Hara 1999, 2002; Tooker et al. 2006; Stireman 2008). The present study provides some initial data on the diversity and temporal distribution of Tachinidae in Southwestern Ohio, USA.