Introduction Current studies on the relationship between periodontitis and carotid atherosclerosis (CAS) remain inconclusive. This updated meta-analysis was conducted to evaluate the relevant observational studies to drive a definite conclusion. Methods Four major databases were searched for observational studies regarding the relationship between periodontitis and CAS published up to 14 December 2023. Software STATA 14.0 was used to calculate pooled odds ratios (OR) and 95% confidence interval (CI) in random effects model. Results Twenty-six articles were finally included. Periodontitis was significantly associated with CAS (OR = 1.97, 95% CI = 1.64 - 2.36
p = 0.000)，however, statistical heterogeneity among studies. Sensitivity analysis indicated our results were robust. Although publication bias was observed, odds ratio corrected by the trim-and-fill method was still increased (OR = 1.30, 95% CI = 1.06 - 1.58
p = 0.000). Conclusion The findings revealed a significant association between periodontitis and CAS. However, long-term randomized controlled trials should be conducted to identify the causality.