Supervisors may be prone to implicit (unintentional) bias when granting procedural autonomy to trainees due to the subjectivity of autonomy decisions. The authors aimed to conduct a systematic review and meta-analysis to assess the differences in perceptions of procedural autonomy granted to physician trainees based on gender and/or race. MEDLINE, Embase, CENTRAL, Scopus, and Web of Science were searched (search date: January 5, 2022) for studies reporting quantitative gender- or race-based differences in perceptions of procedural autonomy of physician trainees. Reviewers worked in duplicate for article selection and data abstraction. Primary measures of interest were self-reported and observer-rated procedural autonomy. Meta-analysis pooled differences in perceptions of procedural autonomy based on trainee gender. The search returned 2,714 articles, of which 16 were eligible for inclusion. These reported data for 6,109 trainees (median, 90 per study) and 2,763 supervisors (median, 54 per study). No studies investigated differences in perceptions of autonomy based on race. In meta-analysis of disparities between genders in autonomy ratings (positive number favoring female trainees), pooled standardized mean differences were -0.12 (95% confidence interval [CI], -0.19 to -0.04; P = .003; n = 10 studies) for trainee self-rated autonomy and -0.05 (95% CI, -0.11 to 0.01; P = .07; n = 9 studies) for supervisor ratings of autonomy. Limited evidence suggests that female trainees perceived that they received less procedural autonomy than did males. Further research exploring the degree of gender- and race-based differences in procedural autonomy, and factors that influence these differences is warranted.