The question of combined lesions of the oral cavity and internal organs occupy a prominent place among the problems of dentistry nowadays. They allow to reflect the genesis of many diseases that manifest themselves in the oral cavity. Aim of the study was to analyze information on the relationship of diseases of oral cavity and various diseases of gastrointestinal tract. Anatomical and physiological proximity, common innervation and humoral regulation leads to the involvement of organs of oral cavity in the pathological process. Catarrhal gingivitis, stomatitis are often caused by deficiency of vitamins of group B. Above-mentioned deficiency is caused, according to many scientists, by the diseases of gastrointestinal tract. And such diseases of the oral cavity as chronic recurrent stomatitis, lichen planus, chronic recurrent herpetic stomatitis, chronic periodontitis depends on the pathology of the digestive tract. Conclusions. Thus, anatomical and physiological characteristics of children, who suffers from chronic gastrointestinal diseases, make us study the clinical manifestations of dental diseases in these patients. Prospects for further research. Further study of the dental status of children with diseases of the gastrointestinal tract is very valuable.