Plaque control is the most important way in prevention of periodontal disease and caries. On the other hand, tooth brushing is the best and important mechanical way for plaque control. Poor compliance of patients in response to oral hygiene instruction is a common problem. The aim of this study was to evaluate the reasons of poor compliance with brushing in Azadshahr region of YAZD (Iran). 90 Non compliant and 90 compliant men (15-39 years) were recruited and interviewed during home visit. Their knowledge, attitude toward oral heath and their compliance with tooth brushing were evaluated. The results showed that factors in non compliance with brushing were as follows: inadequate knowledge about oral heath. The number of family members, economic status, lack of knowledge about the effect of oral disease on cardio-vascular problems, logistic analysis showed that increase in knowledge about oral heath almost doubled compliance with brushing. Some reasons had been mentioned by the non compliant people for their non compliance with brushing was as follows in descending order: being tired because of daily work being busy.The most important factors in compliance with brushing were as follows in descending order: Prevention of dental caries Having good breath.

Key words: Tooth brushing- Compliance- Oral hygiene