The timing of the dietary shift from foraging to maize agriculture, and the speed at which such practices were adopted, are important considerations in the cultural evolution of the New World. In the southern Lower Mississippi Valley, maize agriculture traditionally was believed to have been practiced during the Coles Creek period (A.D. 700–1200); however, direct evidence for maize is lacking in the archaeological record prior to A.D. 1000. The present study examines Coles Creek diet from a bioarchaeological perspective. Oral-health indicators, including abscesses, antemortem tooth loss, calculus, carious lesions, periodontal disease, and tooth wear, were evaluated in a regional, temporal context. Data were collected from 288 dentitions from eight sites in the southern Lower Mississippi Valley that range in date from 800 B.C. to A.D. 1200. The sample then was separated into Pre-Coles Creek and Coles Creek categories and statistical analyses were used to assess temporal variation in pathology load. Results indicate that pathology load in the Coles Creek sample is slightly heavier than the Pre-Coles Creek sample; however, the differences are not substantial. Furthermore, data suggest that regional differences in resource exploitation existed between the Lower Mississippi Valley and populations elsewhere in the eastern United States. Specifically, the presence of starchy native plants other than maize in the diet likely contributed to a high pathology load for early hunter-gatherers. Ultimately, data from this study complement the archaeological, botanical, and zooarchaeological records and indicate that Coles Creek subsistence was not based on maize agriculture. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc.