​Background and objectives: Behçet's syndrome is an inflammatory disorder of unknown etiology that has a unique worldwide prevalence and distribution. The aim of this study was to estimate the prevalence of Behçet's syndrome in the world and in Iran using a systematic review and meta-analysis approach.

Material and Methods: Data banks of Ovid, MEDLINE, Rheumatology, Google scholar, Springer, PubMed, Science direct, Wiley, Magiran, SID, Iranmedex and Irandoc from 1990 onwards were searched. All cross-sectional studies relevant to the prevalence of Behçet's in the world and in Iran were studied. Prevalence rate of Behçet's syndrome with 95% confidence limits was calculated. For statistical analysis, prevalence rates were entered in the Comprehensive Meta Analysis (CMA) software. The prevalence of Behçet's was mapped with the Geographic Information Systems (GIS).

Results: In this study, 23 articles were finally accepted. The overall prevalence of Behçet's syndrome in the world was 42.4 per 100000 (95% CI: 0.382 -0.465). Heterogeneity rate with 23 studies was 1127.5, and with 21 studies were 490.3. The highest rates were reported from Turkey with the overall prevalence of 4.2 per 1000 (95% CI: 4.073- 4.327).

Conclusion: Our findings showed that the highest occurrence of Behçet's disease was observed in Turkey, Palestine and Iran. It is also, however, common in Europe, America and other Asian countries.