Nontarget arthropod populations were monitored in both transgenic and nontransgenic corn and soybean fields in western and central Ohio. A total of 24 fields, 12 corn and 12 soybean, were inspected weekly from late June through mid August. Half of the cornfields were Bacillus thuringiensis (Bt) hybrids and half of the soybean fields were Roundup Ready (RR). Sweep net samples in soybean fields and unbaited Pherocon AM yellow sticky traps in both soybean and cornfields were used to collect nontarget arthropods. Soil samples were also taken from all 24 fields to compare soil mite populations. A select group of 15 readily identifiable arthropods composed mainly of beneficial insects commonly found in field crops, were recorded in weekly sweep net and sticky trap samples for later analysis. Sweep net data from soybean fields revealed no significant differences in nontarget arthropods. Yellow sticky trap data from soybean and corn fields found significantly more green lacewing adults (Chrysopa spp.) in six pooled non-RR soybean fields, significantly more rove beetles in one non-Bt cornfield, and significantly more Orius spp. in one Bt cornfield. There were also significantly more soil inhabiting mites at one non-RR soybean field. Based on the abundance of these arthropod populations in paired transgenic and nontransgenic fields, few negative effects on the 15 nontarget arthropods selected can be directly associated with transgenic soybean and corn crops in Ohio.