Purpose: To study the complication and success rates of root-filled teeth restored with zirconia posts in a critical review. Materials and Methods: An electronic literature search in the MEDLINE, Cochrane Library, Ovid-EMBASE, and Chinese National Knowledge Infrastructure (CNKI) databases was undertaken in December 2018. Other databases were also searched for gray literature, and the electronic search was complemented by a manual search in the related reviews and references of full-text articles. Initial screening of the titles and abstracts of eligible studies was conducted by two independent reviewers in duplicate. Complication and success rates were extracted from the included studies and then pooled using a random- or fixed-effects model. Poisson regression was used to study the effect of core materials (resin vs composite). Results: Among 431 screened articles, 2 prospective and 3 retrospective studies met the eligibility criteria and were included. The pooled data showed that zirconia posts had a favorable 3-year success rate of 97.4% (95% confidence interval [CI] 95.7% to 98.8%). The estimated 3-year catastrophic complication (ie, tooth extraction) rate was 0.09% (95% CI 0% to 1.67%), and the estimated 3-year noncatastrophic complication rates were 0.24% (95% CI 0% to 1.16%) for post complications, 0.78% (95% CI 0% to 4.29%) for crown complications, and 0.03% (95% CI 0% to 0.63%) for endodontic failures. Conclusion: Based on the limited number of clinical cohort studies, zirconia posts appear to be suitable for use in post-and-core systems. However, the studies included in this critical review had a relatively high risk of bias, and further well-designed clinical studies, especially long-term randomized controlled trials, are required to confirm these findings.