Background/AimsThe clinical manifestations of Behcet disease (BD) have been reported to differ according to country, region, and race. Gender, onset age, and human leukocyte antigen (HLA)-B51 have also been known as the factors that influence the clinical features of BD. The aim of this study is to investigate the clinical phenotypes of Korean patients who visited the rheumatology clinic with BD with respect to gender, onset age, and HLA-B51.MethodsTotal 193 Korean patients (129 females and 64 males) fulfilling the international criteria for BD were retrospectively assessed.ResultsThe mean age at disease onset and disease duration of the BD patients were 32.2 ± 11.1 and 14.2 ± 9.3 years, retrospectively. Females suffered more frequently from genital ulcers (90.7% vs. 75.0%, p < 0.01), peripheral arthritis (67.4% vs. 43.8%, p < 0.01), and inf lammatory low back pain (38.8% vs. 23.4%, p = 0.03) than males, while skin involvement was more frequent in males than in females (90.6% vs. 75.2%, p = 0.01). The patients with late onset of BD (> 40 years) suffered from neurologic involvement (15.9% vs. 4.2%, p = 0.007) more frequently than those with early onset of BD. The patients with HLA-B51 showed earlier onset of disease than without HLA-B51 (28.3 ± 11.4 years vs. 33.8±11.6 years, p = 0.02) and the neurologic and gastrointestinal involvements were more frequent in the patients without HLA-B51 than with HLA-B51 (17.2% vs. 2.5%, p = 0.02 and 20.7% vs. 2.5%, p = 0.01, respectively).ConclusionsThe clinical phenotypes in Korean patients with BD may be influenced by gender, onset age and HLA-B51.