Abstract: INTRODUCTION: Behcet’s Disease (BD) is classified among vasculitides, but its clinical picture is very distinctive and can be easily differentiated from the others. BD was originally seen along the Silk Road, but due to immigrations it is now seen everywhere in the world. There are many reports on clinical manifestations of BD from different parts of the world. The majority are case series except two nationwide surveys, one from Iran1, and the other from Japan2. Clinical symptoms vary in those reports and some think BD is a different disease in different parts of the world. The BD-SIG tried to analyze BD on a same protocol to see if there were differences in clinical manifestations in some of the countries of APLAR region, where BD is most seen. Data from Hong Kong, India, Iran, and Singapore are available up to now. An analysis will be made on these data. More data will become available later. MATERIAL AND METHODS: A questionnaire of 90 items was filled with the data of patients (fig 1). Computer analysis of the data was performed. Item percentages were compared according to their confidence interval (CI) calculated at 95%. RESULTS: The sex distribution was approximately equal in both sexes in all countries except in India where the male frequency was higher, 64%. However, regarding the CI (13.3) there was no statistically significant difference between them. First Manifestation of the Disease: Oral aphthosis as the first symptom was seen in 64% of patients in India and 80% from Iran, while it was reported in 100% from Singapore and Hong Kong. The difference was statistically significant (p<0.001). The same was seen with genital aphthosis (24%, 10%, 65%, 81%), uveitis (12%, 10%, 35%, 35%), Joint manifestations (18%, 5%, 57%, 54%), and skin manifestations (24%, 8%, 89%, 73%). Clinical Manifestations: There was a statistically significant difference between oral aphthosis in Iran (96%) and Singapore and Hong Kong (100% each), while the difference with India (96%) was non significant. Genital aphthosis was less frequent in Iran (65%) than in India (82%) and Hong Kong (81%), while it was only 72% in Singapore. No significant difference was seen in the percentage of patients having skin manifestations, while the percentage of individual skin lesions was very different. Erythema nodosum was very frequent in Hong Kong (74%), India (52%), and Singapore (38%) than Iran (22%). No significant difference was seen for ocular lesions between Iran and India while the difference between Iran (56%) and Hong Kong was significant (35%). There was no difference in Joint manifestations between India (68%), Singapore (62%), and Hong Kong (54%), while it was less frequently seen in Iran (35%). Gastro-intestinal manifestations were the same in Iran, India, and Hong Kong, while they were much more frequently reported in Singapore (35%). No other major differences were seen with clinical manifestations. Laboratory Investigations: The pathergy was positive more frequently in Iran than in the other countries. This may be due to the technical differences and to the reading process of the results. Results for ESR and urinalysis were the same in all countries. Results of HLA-B5 were available from Iran and India. There was no significant difference between them. CONCLUSION: Although there were some differences between the results from Iran and other countries, the general pattern of the disease seemed to be the same in all of them. More data are necessary to draw a real picture of the disease in APLAR countries.