peer reviewed ; [en] OBJECTIVE: To develop and validate the Reflux Sign Assessment (RSA), a clinical instrument evaluating the physical findings of laryngopharyngeal reflux (LPR). METHODS: A total of 106 patients completed a 3-month treatment based on the association of diet, pantoprazole, alginate, or magaldrate with the LPR characteristics (acid, nonacid, mixed). Forty-two asymptomatic individuals completed the study (control group). The RSA results and reflux finding score (RFS) were documented for the LPR patients at baseline and after treatment. Intrarater reliability was assessed through a test-retest blinded evaluation of signs (7-day intervals). Interrater reliability was assessed by comparing the RSA evaluations of three blinded otolaryngologists through Kendall's W. Responsiveness to change was evaluated through a comparison of the baseline and 3-month posttreatment findings. The RSA cutoffs for determining the presence and absence of LPR were examined by receiver operating characteristic (ROC) analysis. RESULTS: A total of 102 LPR patients completed the study (68 females). The mean age was 53 years. The mean RSA at baseline was 25.95 ± 9.58; it significantly improved to 18.96 ± 7.58 after 3 months of therapy (P < .001). RSA exhibited good intra- (r = 0.813) and interrater (Kendall's W = 0.663) reliabilities (N = 56). There was no significant association between the RSA, gastrointestinal endoscopy findings, and the types of reflux (acid, nonacid, or mixed) according to impedance-pH monitoring. An RSA >14 may be suggestive of LPR. CONCLUSION: The RSA is a complete clinical instrument evaluating both laryngeal and extralaryngeal findings associated with LPR. The RSA demonstrated high intra- and interrater reliabilities and responsiveness to change.