The diagnosis and interpretation of lesions of the dentition and masticatory apparatus are useful for identification of the lifestyle of ancient populations. Paleopathological investigations of teeth provide information about the type of diet and alimentary resources. Diseases of the teeth are relatively easy to study in earlier populations, due to the resistance of dental hard tissues to post mortem degradation. The term the Bijelo Brdo Culture refers the period from the 10th to the 13th century. This is a professional term which has been used for over 80 years to designate different types of material remains with common characteristics found in early medieval graves from southern and south-eastern Slovakia, Hungary, south-eastern Austria, continental Croatia, Slovenia, western Romania and Vojvodina. The name of the culture is derived from the eponymous site near Osijek in Croatia. The development of the Bijelo Brdo Culture was a complex process influenced by numerous elements, including the cultural heritage of previous periods, Byzantine influences, ethnic migrations, and the development of medieval states. The bearers of the Bijelo Brdo Culture have now been identified as Slavs and Hungarians, with the understanding that the Slav component was heterogeneous.The aim of this study was to evaluate the alveolar bone pathology defined by the presence of dental caries, antemortem tooth loss, and occlusal surface wear. Recorded dento-alveolar lesions together with paleodemographic data were used for reconstruction of the dietary pattern. Skeletal remains from the medieval Bijelo Brdo cementery near Osijek in eastern Croatia were excavated at the end of the 19th and beginning of the 20th century. The material was stored in the Archeological Museum in Zagreb. Skulls of 85 individuals were investigated. A total of 1064 teeth were examined for caries prevalence, antemortem tooth loss, and occlusal surface wear. The determination of sex was made according to cranial morphology. Age determinations were based on cranial suture closure, eruption status and/or tooth wear patterns. Almost 50 per cent of the examined individuals exhibited caries in some form. The prevalence of carious teeth expressed as a percentage of the teeth available for examination was 9.6%.Most of the examined teeth showed a moderate amount of attrition. Cultural and socioeconomic factors strongly influence the status of teeth and their supporting structures. Many studies have pointed out a relationship between the incidence of caries and the type of economy. The lowest caries frequencies have been recorded in hunting-gathering-fishing populations, with the highest among agriculturists. The increase in caries was related to a greater consumption of carbohydrates, in association with new systems of cooking and processing food. The lower socio-economic classes in the Middle Ages had a diet based essentially on cereals (bread represented more than 70% of the food intake) accompanied by lard, whereas the consumption of proteins (fresh meat and fish) was generally low and infrequent. According to the paleodemographic data, the relatively high caries prevalence, and the moderate occlusal surface wear, we can conclude that the early medieval inhabitants from Bijelo Brdo were mainly agriculturists and hunters with a diet based on cereals.