To compare voice-related outcomes of type 1 thyroplasty using Gore-Tex® between patients with and without augmentation injection laryngoplasty (IL) prior to surgery. Forty-five patients who underwent Gore-Tex® thyroplasty at a single institution by a single surgeon between November 2016 and February 2019 were identified as those who previously had IL (n = 20) and those without IL (n = 25). Pre- and post-operative voice-related primary outcomes were evaluated using the GRBAS, and CAPE-V auditory-perceptual rating scales and secondary outcome were evaluated using the VRQOL. Pre- and post-operative voice samples were blinded, randomized, and analyzed by 3 voice-specialized speech pathologists to obtain CAPE-V scores. The VRQOL and GRBAS scores were obtained from retrospective chart review. Student's t test with a paired one-tailed distribution was used for comparisons within groups and 2-sample equal variance for comparisons between groups. Intraclass correlation coefficient determined interrater agreement. GRBAS, and VRQOL significantly improved post Gore-Tex® thyroplasty. There was no difference in improvement between patients who received pre-surgery IL and those who did not in either GRBAS or VRQOL scores, but CAPE-V showed significant improvement in the IL group. A strongly positive correlation was demonstrated between the severity of CAPE-V pre-op score and the overall improvement following surgery for both groups combined. Patients with vocal fold paralysis have a significantly better voice after Gore-Tex® thyroplasty by self-report (VRQOL) and assessment by trained voice professionals (GRBAS). Having IL prior to surgery does not adversely affect later surgical outcomes. This paper represents one of the largest analyses of voice quality outcomes of Gore-Tex® thyroplasty using validated patient scales and randomized blinded analyses.