Listeria monocytogenes can be present in poultry processing and further processing plants, where it can colonize floor drains. This is a concern as the potential exists for cross-contamination of product contact surfaces or even fully cooked product. Self-contained chlorine dioxide-generating and delivery pods were tested as a means to sanitize uninoculated floor drains and L. monocytogenes-inoculated model floor drains. Free-swimming and attached bacteria were enumerated in drains. Standing water and the inner surface of treated drains had significantly lower bacterial numbers than did untreated drains.