Objective: The most important genetic factors known in the pathogenesis of Behçet's disease (BD) is HLA-B51. It has been shown that HLA-B51 positivity is high in countries on the 'Silk Road' where BD is frequent. HLA-B51 is thought to be a prognostic marker that is related to severe clinical forms of BD. In this study, we aimed to investigate the prevalence of HLA-B51 positivity in patients diagnosed with BD and the relationship between the demographic and clinical findings of the patients. Material and Methods: Between March 2013 and 2018, the files of the patients who were diagnosed with BD according to the criteria of the International Study Group for Behçet Disease in dermatology polyclinic of Selçuk University Medical Faculty were reviewed retrospectively. Forty-seven patients (22 women and 25 men) with HLA-B51 were included in the study. Results: In our study, no correlation was found between HLA-B51 positivity and gender, age at onset, family history, clinical findings (such as oral and genital ulcer, papulopustular eruption, erythema nodosum, pathergy test positivity, thrombophlebitis, ocular involvement, arthritis) and systemic manifestations. Conclusion: In previous studies, conflicting results have been reported on the relationship between HLA-B51 and BD manifestations in different ethnic groups. In our study, no statistically significant correlation was found between HLA-B51 positivity and demographic and clinical findings of Behçet patients. We believe that there is a need for larger comparative prospective studies investigating the relationship between HLA-B51 and BD in different ethnic groups.