To perform a quantitative computed tomography (CT) assessment of short- and long-term outcomes of autologous fat injection augmentation in patients with unilateral vocal fold paralysis. Retrospective case series. Twelve patients who had undergone autologous fat injection augmentation for unilateral vocal fold paralysis in our hospital between 2011 and 2015 were enrolled in this study. The autologous fat for injection was acquired from periumbilical subcutaneous tissue and was injected orally using a special-purpose laryngeal injection needle. To evaluate the injected fat at the follow-up assessments, CT was performed at several times after surgery in clinical practice. All thin-section CT images were transferred to a workstation, and the volume of the injected fat was calculated. Patients comprised 6 men and 6 women with a mean age at the time of surgery of 62.9 years (range, 46-82 years). The actual injected fat volume was 1.1-2.5 ml (mean, 1.6 ml). In seven patients assessed by CT two days after surgery, the average residual rate of the injected fat was 63.9%. The mean residual rates of the injected fat were 30.0% at 3 months, 33.7% at 6 months, 29.2% at 12 months, and 32.0% at 24 months. Although the injected fat volume decreased within the first three months and the residual rate of the injected fat was 30.0% at three months after injection, the residual fat volume remained at the same level for 24 months after injection. 4.