Mesowear analysis is a powerful tool for paleodiet reconstruction in ungulates. In this study, we apply this method to archeological data. We conduct mesowear analysis on cheek teeth of medieval horses from the Levänluhta site in Ostrobothnia, western Finland and, for comparison, we study medieval and post-medieval horse teeth from Viljandi and Tallinn, Estonia. Our results show attrition-dominated mesowear indicating browsing diet for the medieval Levänluhta horses, while the Viljandi horses have mesowear indicating more mixed diet. Mesowear on teeth from Tallinn horses suggest primarily grazing-like abrasive diet. Differences maybe due to different diet of horses in Finland and Estonia, or may point to seasonal differences in diet and thus indicate different times of death for these horses.