Objective: To validate the Trans Woman Voice Questionnaire (TWVQ) in Brazilian Portuguese (BP). Method: This methodological study was approved by the Research Ethics Committee (n. 4.219.399). The validation followed the recommendations of the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). The validation process included content, construct, and criterion validity; test-retest reliability and internal consistency, and responsiveness. The sample consisted of five voice specialists, 85 transgender women, and 40 cisgender women. Voice specialists assessed the TWVQ using the Content Validity Index (CVI). Transgender participants completed the TWVQ three times: initially, after 2 to 14 days, and post-voice intervention. Cisgender women completed the TWVQ once. Results: Content validation yielded an overall CVI of 0.89. For Item-level CVI (I-CVI), 13 of the 30 items scored below the expected threshold (<0.8). After item revision, the TWVQ was reapplied to the target population, and all items were deemed adequate. In construct validation, exploratory factor analysis indicated the removal of items 1 (difficulty hearing in noisy environments) and 26 (strangers’ reactions to voice), due to low communalities. The final BP version of the TWVQ consisted of 28 items across three factors, with structure confirmed via confirmatory factor analysis (CFA) and a Standardized Root Mean Square Residual (SRMR) of 0.067. Internal consistency yielded Cronbach’s alpha of 0.971 for the full instrument, 0.962 for factor 1, 0.940 for factor 2, and 0.729 for factor 3. Test-retest reliability produced an Intraclass Correlation Coefficient (ICC) of 0.959 for the full instrument, 0.976 for factor 1, 0.944 for factor 2, and 0.964 for factor 3. Responsiveness showed significant differences via the Wilcoxon test, with lower TWVQ scores post-intervention for total score (Z=-4.862; p<0.001), factor 1 (Z=-4.252; p<0.001), factor 2 (Z=-2.701; p=0.007), and factor 3 (Z=-4.862; p<0.001). In criterion-related validity, the TWVQ effectively distinguished transgender from cisgender women across all factors and in the total score (p<0.001 for all). Conclusion: The BP version of the TWVQ, with 28 items and three factors, demonstrated reliability and validity.