Background: Despite a number of studies, the optimal timing of completion thyroidectomy is still controversial. This systematic review and meta-analysis aims to compare the outcomes of early versus delayed completion thyroidectomy regarding post-operative complications. Methods: We performed a systematic review in electronic databases including: bumped, Scopus, Medline and Google Scholar to identify relevant studies. Eligibility criteria included studies comparing the outcomes of early versus delayed completion thyroidectomy with no language restriction. Publication bias was assessed by funnel plot, and Heterogeneity was assessed using I 2 statistic. Finally, pooled odds ratios (OR) with a 95% confidence interval (CI) was reported for comparing the overall complications rate. Results: Eventually 7 studies were included. Delayed completion thyroidectomy was found to be associated with significantly lower rates of post-operative complications (OR =1.55; 95% CI, 1.00-2.42; Z=1.95; P=0.05) with low heterogeneity (I 2 =0%, P=0.55), and low risk of publication bias. The rate of transient hypocalcemia and persistent hypocalcemia were 8.97% and 1.52% in early completion thyroidectomy group, and 8.2% and 0.72%, in delayed completion thyroidectomy group. Transient vocal cord paresis occurred in 5.38% of the early CT group versus 3.27% in the delayed CT group. Conclusions: This review is the first to summarize the outcome of early verse delayed completion thyroidectomy. The result of our systematic review and meta-analysis suggest that delayed completion thyroidectomy is associated with lower rate of post-operative complications compared to early completion thyroidectomy.