Technical Abstract: Eight Bacillus thuringiensis (Bt) transgenic sweet corn hybrids were evaluated (with two controls) for their efficacy against two ear-feeding insects; the corn earworm [Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)], and the fall armyworm (Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). The mortality of corn earworm was significantly higher in the Bt-transgenic sweet corn hybrids than that in the controls (‘Garrison’ and ‘Serendipity’) but, mortality of fall armyworm was not different among the Bt and non-Bt hybrids. In addition, the weight of live larvae showed that the transgenic Bt-genes have significantly reduced the larval weight for both insects, except in ‘BC0808’.