The widespread use of transgenic Bt cotton varieties in the southeastern U.S has allowed many farmers to dramatically reduce applications of broad-spectrum insecticides. As a result, insect pollinators, including honey bees, are returning to cotton fields. This 2-year study investigates the relationship between cotton production and proximity of supplemental honey bee sources, using two irrigated Bt cotton fields. During year 1, both per boll cotton yield indicators and honey bee foraging activity declined with increasing distance from bee sources that were placed in adjacent corners of the bee field. No such trends were observed between yield indicators or bee activity and distance from field corners in the non-bee field. Similar trends were found during year 2 of the study, when status of the fields (bee or non-bee) was reversed. These results suggest a significant positive impact of supplemental honey bees on cotton yield.