Abstract: Historical Background: Behcet's Disease (BD) is mainly seen along the Silk Rout This very peculiar geographical distribution arises the question that weather the disease was spread from east to west or from west to east. The epidemiology of BD in Iran shows that the genetic background is related to the East Asians (Mongoloid) race. This finding suggests that BD was spread along the Silk Route from East to West. Geographical Area: Middle East is situated between Europe and East Asia. It comprises countries from Asia and Africa (Libya, Egypt, Jordan, Israel, Lebanon, Syria, Turkey, Iraq, Iran, Saudi Arabia, Yemen, Kuwait, Qatar and Emirates). For some geographer it includes the northern part of Africa up to Morocco. There is a lack of data from many countries of the Silk Route, mainly from Central Asia from the former Soviet Union countries (Kazakhstan, Turkmenistan, Uzbekistan, Kyrgyzstan, Tajikistan and Azerbaijan) and from South East Asia. Prevalence: BD has its highest incidence in Japan, Korea, China, Turkey and Iran. In Arab countries of the Middle East and around the Mediterranean Basin, the incidence of BD decreases. The disease is extremely rare in India, Burma, Thailand, Cambodia, Malaysia, Singapore and Philippines. The estimated prevalence for 10,000 inhabitants was 1.35 in Japan, 1.4 in China, 1.67 in Iran, 2 in Al Qassim region of Saudi Arabia, 0.21 in Kuwait and 0.76 in Egypt. An analysis of all inhabitants of a village in the northern part of Turkey showed a prevalence of 37 for 10.000, while another study in 9 villages near Istanbul showed 8 patients for 10,000. It is always difficult to generalize the figures obtained in some villages to all the country, especially in Middle Eastern countries, where intermarriage is frequent. Sex: The disease was seen more frequently in male patients in all countries of the Middle East and Asia, except for Japan and Korea. The male to female ratio was 0.98 to 1 for Japan, 0.63 for Korea, 1.14 for Iran, 1.8 for India, 1.78 for Turkey, 3 for Iraq, 3.4 for Saudi Arabia, 2.8 for Jordan, 5.37 for Egypt and 2.45 for Morocco. In Israel, an old data from 1975 shows a male to female ratio of 4.86 to 1, whit new data from 1997 shows 0.64 to 1. Age: BD may be seen in every age, but it is mainly seen in young adults. The mean age at the onset of the disease was 35.7 years for Japan, 29 for Korea, 26.2 for Iran, 33.1 for India, 23.3 for Turkey, 29.4 for Iraq, 29.3 for Saudi Arabia, 30.1 for Jordan and 26.2 for Egypt. In Israel, an old data front 1975 shows a mean age of 27.8 years, while the new data from 1997 shows a mean age of 30:7 years in adults only.