Objective: To validate the previously translated Brazilian Portuguese version of the Leicester Cough Questionnaire (LCQ-Br). Methods: This cross-sectional study was approved by the Research Ethics Committee, and all ethical standards required by Brazilian legislation were upheld. Validation procedures followed the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN). Psychometric properties assessed included construct validity (structural validity), criterion validity (concurrent validity), reliability (internal consistency and test-retest reliability), and responsiveness. The sample comprised 98 patients diagnosed with chronic cough (CC), with a mean age of 49 years and 79% female participants. Data collection included an initial assessment in which all participants completed a sociodemographic questionnaire, the Brazilian version of the Leicester Cough Questionnaire (LCQ-Br), the Cough Severity Index (CSI-Br), the Laryngeal Hypersensitivity Questionnaire (LHQ-Br), and three self-assessment instruments for laryngeal sensitivity, cough frequency, and intensity. Participants completed the LCQ-Br on three additional occasions, with a 2–14-day interval from the initial assessment and before and after a speech therapy intervention for CC. Data analysis was conducted using IBM SPSS Statistics 29 and IBM SPSS Amos 29. Results: Structural validity confirmed the LCQ-Br factor structure with an SRMR of 0.064. Concurrent validity showed significant negative correlations between the LCQ-Br’s physical, psychological, social, and total scores and self-reported laryngeal sensitivity, cough frequency, and intensity, as well as with all CSI-Br factors, and significant positive correlations with the LHQ-Br (p<0.001 for all). Internal consistency reliability yielded Cronbach’s alpha coefficient ranging from 0.869 to 0.952, and test-retest reliability demonstrated an intraclass correlation coefficient between 0.332 and 0.629. Responsiveness analysis indicated a significant post-intervention reduction in LCQ-Br scores for the physical (p=0.001), psychological (p=0.023), and total (p=0.009) domains. Conclusion: The LCQ-Br is a valid, reliable, and responsive instrument for assessing the health status of patients with CC and has potential for use in both clinical practice and research.