Hygiene of the teeth and mouth are the indicator of dental and oral health. Children with special needs in physical aspects include disorders such as blind, hearing impairment, mentally disabled, disabled and autistic. Someone with hearing impairment will have an influence in acquaring understanding of dental and oral health maintenance. It is necessary to consider the condition of dental and oral health in children between ages of 10 and 16 as a mixed dentition period. Children with special needs have a greater risk of tooth and mouth disease because of their low motor and cognitive abilities. The aim of this study was to determine the relationship between knowledge with the level of dental and oral hygiene (OHI-S) in children with hearing impairment. This study was an analytic observational study with a cross sectional design. Subjects were taken by total sampling technique, the number of subjects are (n=23). The data are statistically analyzed with the Saphiro-Wilk test (p>0,05) and the Pearson correlation test. The results of the study on the Pearson correlation test found a significance value of 0.011 (p<0,05) indicating a significant correlation. Pearson correlation value -0.522 means that the strength of the medium correlation and the direction of the negative correlation indicate that higher knowledge variable will has lower the OHI-S variable. The conclusions was there were a significant relationship between the level of dental and oral health knowledge with dental and oral hygiene status (OHI-S) in children with hearing impairment in SLB 1 Bantul Yogyakarta.