Nowadays it is known that health education dissemination combines medical and hygienic knowledge because education in public hygiene habits in order to preserve and strengthen health and improve health culture is one of the main methods of prevention of dental diseases. It is proved that there is a direct link between insufficient knowledge of hygiene and dental status. In the prevention of dental caries in children weighing place rational and balanced diet place an important role, which belongs to the endogenous factors of teeth resistant to adverse factors. In the development of dental caries an important role belong to the excessive carbohydrate intake, contributing to metabolic disorders in the body and in solid tissues, respectively. The excessive consumption of sweets, in turn, negatively affects the structure of hard tissues of children. It is known that there is a relationship between the state of oral and somatic pathology of various origins. One of the most common diseases of childhood diseases of allergic genesis is asthma. Treatment of asthma involves the oral administration of ?-adreno-blockers and inhalator of glucocorticosteroids that is certainly reflected in the composition and properties of oral fluid and, as a result, in oral hygiene. Therefore, the study of hygiene knowledge and dietary habits in children with asthma is quite important as promote the prevention of dental diseases in those children. The aim of the study is to evaluate the level of hygiene knowledge of children with asthma. Results.172 children aged 7, 12 and 15 years were examined for the evaluation the level of hygiene knowledge. To study the hygiene knowledge in the children surveyed had carried out a survey on questionnaires, in which children answered the following questions: "Do you rinse your mouth after using sprays?", "How many times a day do you brush your teeth?", " How often do you change your toothbrush? ", " How often do you change the toothpaste? ","What kind of food do you like ", «How often do you use a sweet?". The survey results were statistically processed with using of the Student's criterion. Results. Analysis of the frequency of teeth brushing was showed that the majority of children do this 1 per day that indicate a lack of oral care among the surveyed children. So, 68,5 ± 7,5% of 7 years-old children brush their teeth once a day, while at age 12 the figure drops to 41,6 ± 5,03% (p 0,05). The vast majority of children gave answers that they change the toothpaste 1 time in half a year. It should be noted, that less often, such as 1 per year, change toothbrush by the 15-years-old children (41,7 ± 5,03%) was noted, while among 12 years-old children the proportion of children who followed a similar regime of the replacement toothbrush was in 6 times less and is 25 ± 4,4% of children, respectively (p 0,05). On average, 60 ± 9,2% of respondents preferred meat consumption. Fish consumption somewhat was limited among children with asthma. Conclusion. Overall, the survey found the insufficient hygiene knowledge on oral care of children with asthma, as well as the prevalence of cariogenic products in the diet. The findings suggest that improving of hygiene knowledge and correction of nutrition in children suffering from asthma is an important and timely task, as it may improve both dental health and general health of the entire body.