Recent in vitro studies have suggested a potential role for antimony as a confounder in human health studies related to arsenic in drinking water. We measured tube-well water concentrations of antimony and arsenic in the Pabna region of Bangladesh, where arsenic concentrations are known to be elevated and the concentrations of antimony have not yet been thoroughly documented. Two hundred forty-five tube-well water samples were collected from various regions in Pabna, Bangladesh, as part of an ongoing case-control study. Water samples were analyzed for arsenic and antimony concentrations by inductively coupled plasma-mass spectrometry using U.S. Environmental Protection Agency method 200.8. The arsenic concentrations in the tube-well water samples ranged from < 1 microg/L to 747 microg/L. All 245 water samples had antimony concentrations < 1 microg/L. Based on consideration of the concentrations used the in vitro studies compared with field-observed concentrations, our results do not support the hypothesis that antimony would be a significant confounder in observed relationships between arsenic exposure through drinking water and potential health outcomes in Pabna, Bangladesh.