This study took a tritrophic approach to examining the presence of Bt toxin (Cry1Ac) in the food web of predatory heteropterans common to cotton fields. Ingestion of the toxin by the predatory bug Geocoris punctipes was examined by quantifying the toxin concentration in the feces and bodies of the predators at varying time intervals after drinking purified toxin in water droplets. In the greenhouse, heteropteran predators (G. punctipes, Orius insidiosus, Nabis roseipennis and Podisus maculiventris) were exposed to beet armyworm larvae, Spodoptera exigua (BAW) on Bt-transgenic and non-Bt cotton plants and the concentration of Bt toxin in prey and predators was calculated. Also, the amount of Cry1Ac toxin in plants, in prey (Aphis gossypii and lepidopteran larvae) and in predatory heteropterans (G. punctipes, O. insidiosus, N. roseipennis and P. maculiventris) was quantified in field collections during the cotton-growing season. G. punctipes was able to ingest Cry1Ac toxin from solution. Despite occasional feeding on plants, predators confined on Bt plants failed to acquire detectable levels of Bt toxin. Toxin concentration in BAW larvae was reduced in the greenhouse and field compared to the toxin concentration in the Bt cotton plants. Cry1Ac toxin, also, was detected in predators confined on Bt plants with BAW larvae fed Bt plants. However, no toxin was detected in any of four predators from field collections. The results suggest that the feeding behavior of predatory heteropterans in the field may minimize the likelihood of contact with Bt toxin directly from plants or acquired by the prey.