Objectives-The aims for this study were to determine the prevalence of sleep-bruxism among young children, explore child behavior problems that may be associated with sleep-bruxism, and identify relations among sleep-bruxism, health problems, and neurocognitive performance.Methods-The current study was a retrospective analysis of parent report surveys, and behavioral and neurocognitive assessments. Parents of 1953 preschool and 2888 first grade children indicated their child's frequency of bruxism during sleep. A subsample of preschool children (n = 249) had additional behavioral, as well as neurocognitive assessments. Among the subsample, parents also reported on their child's health, and completed the Child Behavioral Checklist; children were administered the Differential Ability Scales, and Pre-Reading Abilities subtests of the Developmental Neuropsychological Assessment.Results-36.8% of preschoolers and 49.6% of first graders were reported to brux ≥ 1 time per week. Among the preschool subsample, bruxing was independently associated with increased internalizing behaviors (β = .17). Bruxism was also associated with increased health problems (β = .19), and increased health problems were associated with decreased neurocognitive performance (β = .22).Conclusions-The prevalence of sleep-bruxism was high. A dynamic and potentially clinically relevant relation exists among sleep-bruxism, internalizing behaviors, health, and neurocognition. Pediatric sleep-bruxism may serve as a sentinel marker for possible adverse health conditions, and signal a need for early intervention. These results support the need for an interdisciplinary approach to pediatric sleep medicine, dentistry, and psychology.