We studied the presence of linear enamel hypoplasias (LEHs; tooth defects associated with physiological stress) in caribou (Rangifer tarandus). A timeline of tooth enamel development was determined by radiographic examination of 48 mandibles from caribou aged 3–24 months old. We examined mandibles from the Bluenose East (n = 56) and Bluenose West (n = 15) caribou herds in the Northwest Territories and Nunavut, Canada, for LEHs and 21.1% (15/71) were affected. We concluded that LEHs do occur in caribou and tracking these over time may provide a tool to track population dynamics in extant wildlife. © 2012 The Wildlife Society.