Objective: To develop and validate questionnaire scales that can be used in research to investigate the presence of childhood SRBDs and prominent symptom complexes, including snoring, daytime sleepiness, and related behavioral disturbances.Background: Obstructive sleep-related breathing disorders (SRBDs) are common but usually undiagnosed among children. Methods to help identify SRBDs without the expense of polysomnography could greatly facilitate clinical and epidemiological research.Methods: Subjects were children aged 2-18 years who had polysomnographically-confirmed SRBDs (n=54) or appointments at either of two general pediatrics clinics (n=108). Parents completed a Pediatric Sleep Questionnaire which contained items under consideration for inclusion in desired scales.Results: Item reduction, based on data from a randomly selected 50% of the subjects (group A), produced a 22-item SRBD score that was strongly associated with diagnosis of an SRBD (P<0.0001) in a logistic regression model that accounted for age and gender. Diagnosis was also strongly associated with subscores for snoring (four items, P<0.0001), sleepiness (four items, P=0.0003), and behavior (six items, P<0.0001) among group A subjects. The scales performed similarly well among group B subjects, and among subjects of different ages and gender. In group A and B subjects, respectively, a selected criterion SRBD score produced a sensitivity of 0.85 and 0.81; a specificity of 0.87 and 0.87; and a correct classification for 86 and 85% of subjects. The scales showed good internal consistency and, in a separate sample (n=21), good test-retest stability.Conclusions: These scales for childhood SRBDs, snoring, sleepiness, and behavior are valid and reliable instruments that can be used to identify SRBDs or associated symptom-constructs in clinical research when polysomnography is not feasible.