One of the most significant oral health issues worldwide is dental carries, which result from the interaction between bacteria and fermentable carbohydrates and can lead to the destruction of the hard parts of teeth. Despite being preventable, dental caries remain prevalent, affecting approximately half of the world’s population, or 3.5 billion people, with 40% of cases going,untreated. Unfortunately, dental caries has become a serious global public health concern, with a high incidence of cavities among children (60-90%) and adults (100%), frequently causing discomfort and pain. The present study was conducted to assess the effectiveness of video assisted demonstration and find out co-relation between knowledge and practice regarding various brushing techniques to prevent dental carries among Primary Schools children.60 sample were collected by using non-probability convenience techniques through structured knowledge questionnaire the data collected and analysed based on descriptive and inferential statistics. The result showed that the study was statistically not significant at 0.05 level none of the student have adequate knowledge and practice at the time of pre -test but after providing demonstration the knowledge and practice level was increased. The pre-test adequate knowledge is (0%), moderate is 24 (40%), inadequate is 36 (60%) in post-test adequate knowledge is 26 (43%) moderate 34 (57%) inadequate is (0%), in pre-test practice score adequate score is 1(1.67%) moderate, 56(93.3%) inadequate 3(5%) in post- test adequate practice score is 47 (78%), moderate 13(22%), inadequate (0%). The knowledge score for pre-test means and standard deviation values (10.6), (3.3) whereas in post-test (20.0) and (2.37) respectively the calculated “t” value 60.27 was greater than value & df 59 which was p>0.05 level of significant differences between pre-test and post- test level knowledge. The test revealed that there was no significant association of knowledge with selected demographic variables such as Age, Gender, Religion, Previous knowledge, Class, so there were significant with association with association with Age, Gender, Religion, Previous knowledge. Class but there was no significant with other selected demographic variables, were found non-significant at <0.05 level of significance. The practice score for pre-test mean value is (7.55) and standard deviation is (1.18), in post-test mean value (11.37) standard deviation is (1.09) and the calculated t value (25.60) was greater than value & df59 which was p>0.05 level of significant differences between pre-test and post- test level knowledgehence The test revealed that there was no significant association of knowledge with selected demographic variables such as Age, Gender, Religion, Previous knowledge, Class, so there were significant with association with association with Age, Gender, Religion, Previous knowledge. The practice score for pre-test mean value is (7.55) and standard deviation is (1.18), in post-test mean value (11.37) standard deviation is (1.09) and the calculated t value (24.60) was greater than value & df 59 which was p>0.05 level of significant differences between pre-test and post- test level knowledge. The test revealed that there was no significant association of knowledge with selected demographic variables such as Age, Gender, Religion, Previous knowledge, Class, so there were significant with association with association with Age, Gender, Religion, Previous knowledge. Class but there was no significant with other selected demographic variables, were found non-significant at <0.05 level of significance. The study concluded that the demonstration method on various brushing techniques to prevent dental caries among Primary Schools children.