The number of men and women with gastroesophageal reflux disease (GERD) is increasing every year, in addition this disease tends to rejuvenation. Due to the fact that the oral cavity is the initial part of the digestive system, diseases of the gastrointestinal tract (GIT) and the corresponding changes in the oral cavity are closely interrelated. Objective: to determine the qualitative composition of the oral microflora in men and women with gastroesophageal reflux disease. Materials and methods. 20 patients (10 men and 10 women) aged 18 to 74 years with gastroesophageal reflux disease were examined. PCR (polymerase chain reaction) was used for the study, saliva pH and periodontal index PI were measured. Research result. A study of the microflora of the oral cavity showed a high prevalence of periodontopathogenic microorganisms Porpheromonas gingivalis and Prevotella intermidia, 65% of patients (45% men and 20% women), Actinobaccilus actinomecetemcomitans in 45% of patients (15% of men and 30% women), Treponema denticola in 80% of patients with GERD. It was dominated by the acidic environment. The data obtained indicate the relationship between the qualitative composition of the oral microflora and the progression of periodontal disease in men and women with gastroesophageal reflux disease.