The present study aims to shed light on the forced migration of the Arab families from Syria to the Anatolian cities during the World War I, and their return in and after 1918. Contrary to known, the controversial displacement (tehcir) decree of the Committee of Union and Progress (CUP) government dated May 27, 1915 did not only cover the Armenians of Anatolia, but also a number of Arabs from Syria. Approximately 5.000 Arab families settling on the areas under the control of the Fourth Army commanded by Cemal Pasha were forcibly migrated to Anatolia with the claim that "they were inclined to cooperate with and provoked by the French". These 'suspicious' Arab families set forth to the Anatolian cities on the north while the Armenians were on the road to the southern provinces of the Ottoman Empire. The government transferred the Arabs mostly to the inner and northern cities of Anatolia in order to prevent their escaping and association with the Allies. They were placed primarily in the houses abandoned by the migrated Armenians, and were allocated daily wages by the CUP government. All the governmental decrees regulating the forced migration of the Armenians were also in force during the migration of the Arabs. Just before the end of the WWI, on November 30, 1918, the Arab immigrants as well as the Armenians and the Greeks were allowed to return to their hometowns. During the three years of their stay in Anatolia, the Arab families tried to adapt to the new culture, geography and climate. Those settled especially in the northern Anatolia and Thrace had great difficulties to reconcile with the new socio-cultural environment. Under the light of the currently released Ottoman documents, this study gives an account of the Syrian Arab immigrants, the 'suspicious guests' of Anatolia, and analyzes that event within the context of the migration policies of the CUP government and its approaches towards the Arab citizens of the Empire.