Objective: There are limited studies that compare the outcomes of injection laryngoplasty (IL) versus observation in pediatric cardiac surgery patients with vocal fold immobility (VFI). The current study compares outcomes of VFI in pediatric cardiac surgery patients who undergo observation versus those who receive IL treatments. Methods: This is a retrospective case study of 41 pediatric cardiac surgery patients (observation 29 vs IL 12) who had postoperative VFI diagnosed by flexible laryngoscopy from January 1, 2015 to February 1, 2024. The resolution of VFI was based on subsequent normal flexible laryngoscopy and/or modified barium swallow study. The primary outcomes were the rates of gastrostomy tube placement and VFI resolution. Secondary outcomes were time from diagnosis to VFI resolution and time on tube feeds. The two cohorts were compared using two-tailed unpaired t-test, Fisher's exact test, and Mann-Whitney U test as appropriate. Results: There were no statistically significant differences in preoperative and intraoperative characteristics between the two groups. The overall rate of resolution of VFI was 78% (32/41) (observation 83% [24/29] and IL 67% [8/12] [P = .41]). The mean time to VFI resolution was 13.8 months for the IL cohort and 9.9 months for the observation cohort (P = .45). The overall gastrostomy tube placement rate was 44% (18/41) (observation 38% [11/29] vs IL 58% [7/12]% [P = .31]). The mean time on tube feeds for each cohort was the following: observation 13.1 months versus IL 14.9 months (P = .73). Conclusion: There were no statistically significant differences in outcomes between pediatric cardiac surgery patients with VFI who were observed and those who had IL.