Abstract: Introduction: Behcet’s disease (BD) is not rare in children. Its clinical picture differs from adults. The purpose of this study was 1-To find the characteristics of juvenile BD (JBD). 2-To compare JBD with the adult from (ABD) of the disease. Materials & Methods: In a cohort of 3729 patients with BD, different manifestations of the disease, including 100 clinical and paraclinical data, were analyzed. Patients were divided in two groups. 1- Patients who developed their disease before the age of 16 (JBD groups). All of them fulfilled enough criteria to be classified or diagnosed as BD before the age 16, although the diagnosis was delayed in some of them until the adulthood. 2- The adult group (ABD). The two groups were compared by the chi square test. A confidence interval at 95% (CI) was calculated for each item. Results: We had 162 patients with JBD (4.3%, CI=0.7). The male to female ratio was 0.98/1 with no significant difference to ABD (p=0.26). As the presenting sign, oral aphothosis was less common (70%+7 vs. 79%+1.3, p<0.02), but ocular lesions were more common (22%+6.4 vs. 10%+1, p=0.00002). The prevalence of various manifestations of the disease in JBD and their comparison with the ABD were as follow. Oral aphthosis: 88%+5 vs. 96%+0.6 (p<0.000001). Genital aphthosis: 48%+8 vs. 65%+1.6 (p=0.000005). Skin lesions 62%+7.5, vs. 74%+1.4 (p<0.0007), pseudofolliculitis: 55%+8 vs. 66%+1.6 (p<0.004), erythema nodosum: 9%+4.5 vs. 23%+1.4 (p<0.00003). Ocular lesions: 70%+7 vs. 57%+1.6 (p=0.001). Joint manifestations: 31%+7 vs. 39%+1.6 (p= 0.06). Vascular lesions: 4%+3 vs. 9%+1 (p<0.02). G.I. involvement: 9%+4 vs. 8%+1 (p=0.92). Nervous system involvement; 4%+3 vs. 3%+0.6 (p=0.6). Epididymitis: 9%+6 vs. 11%+1.4 of males (p=0.4). Positive pathergy test: 59%+8 vs. 62%+1.6 (p=0.46). HLA-B5: 54%+8 vs. 55%+1.6 (p=0.83), and HLA-B27: 16%+6 vs. 10%+1 (p=0.02). High ESR: 50%+8 vs. 56%+1.7 (p=0.17). Abnormal urine sediment: 12%+5 vs. 11%+1.1 (p=0.66). Positive family history of BD: 8.5%+8 vs. 5.4%+1.3 (p=0.54) and Positive family history of oral aphthosis: 49%+14 vs. 49%+3 (p=0.9). Conclusion: JBD differs from ABD, and is more severe. Mucous and skin lesions are seen less frequently, while ocular lesions are more common (even as the presenting sign). Among the other manifestations, vascular lesions are less common, while the prevalence of HLA-B27 is higher.