Purpose The purpose of this study was to evaluate short- and long-term outcome of injection augmentation with autologous adipose tissue (AAT) and calcium hydroxylapatite injection (CAHA) in patients with a unilateral vocal fold paralysis (UVFP). Design/methods A retrospective cohort study was performed in patients diagnosed with UVFP, who had received injection augmentation with AAT or CAHA. Multidimensional voice analysis was performed before, 3 and 12 months after injection. This analysis included patient self-assessment (Voice Handicap Index-30), perceptual (overall dysphonia grade according to the GRBAS scale), aerodynamic (MPT, s/z ratio) and acoustic (fundamental frequency, dynamic range) parameters. Effects were assessed using a linear mixed model analysis. Results Forty-six patients were available for evaluation, with a total of 53 injection augmentations (AAT n  = 39; CAHA n  = 14). We found significant improvement of patient self-assessment and perceptive voice outcome at 3 months, which were maintained at 12 months. In the CAHA group, s/z ratio and dynamic range of extreme frequencies also improved significantly over time. No statistically significant differences were found between the two treatments (AAT vs. CAHA). No major complications were reported. Conclusion This study, using a guide-line recommended panel of outcome parameters, shows a high success rate of injection augmentation with AAT or CAHA for patients with UVFP at 12 months with significant improvement in most voice outcome parameters, although voices do not completely normalize. There is no significant difference in outcome between the two materials.