This study evaluated the association of level of anxiety in children with and without sleep bruxism (SB). The study was performed with 84 six- to eigth-years-old children, divided into two groups: with bruxism (BG) and without bruxism (CG). Following the criteria purposed by American Academy of Sleep Medicine (AASM) to determine SB, the presence of tooth wear has been verified through clinical examinations, and the parents have answered a questionnaire about their children’s behavior and habits. Additionally, the State-Trait Anxiety Inventory for Children (STAIC) was applied to parents of the selected patients. Data analysis revealed a statistical significant difference between the groups (Student’s t-test, p = 0.0136). Based on the results, anxiety assessment revealed that children with bruxism have reached higher levels in the STAIC scale than the non-bruxism group. Therefore, it indicates a direct relationship between the presence of anxiety disorder and the onset of bruxism in children.