Little attention has been paid to the Taiwanese in Hankou during the period when Taiwan was under Japanese rule. Without knowing their experience, it would be difficult to have the full picture of overseas Taiwanese living in China at that time. However, conducting research on this topic encounters the following problems. Firstly, most Taiwanese who were in Hankou before and especially during World War II preferred to keep silent on their lives and activities in those days. Secondly, materials of appeals or sentences for traitor/ war criminal cases are hard to obtain. This study has access to considerable primary source materials, such as lists of passports issued by the Office of the Governor-General of Taiwan, which shed light on Taiwanese traveling to Hankou before 1937. For the postwar period, historical materials available include name lists composed by the Hankou Police Department and the Hankou Taiwanese Association; the Wuhan Daily (newspaper) with a Taiwanese chief editor after the city fell into Japanese hands; trial records kept by the Second Historical Archives of China (Nanjing) and the National Archives Administration, National Development Council (Taiwan); as well as interview records of Chuang Szu-chuan and Ko Tai-shan, two crucial persons then in Hankou. In addition to compiling a list of Taiwanese in Hankou and exploring as thoroughly as possible their activities there, this paper focuses on their postwar predicaments, such as trials of traitors/ war criminals, as well as how they overcame difficulties and returned safely to Taiwan. A careful scrutiny of the above sources revealed no more than 400 Taiwanese in prewar Hankou, including 145 soldiers recruited by the Japanese to Hankou. Most of those who went there after 1938 were either merchants, or working for the city government or Japanese companies. There were also a few physicians working for the Tung-jen Association (同仁會). After World War II, the Taiwanese there organized the Hankou Taiwanese Association. With the help from all possible sources, most of these Taiwanese were able to return home safely. However, some who worked for the Wang Ching-wei regime were arrested and tried as traitors/ war criminals. They were either found guilty and served prison terms, or cleared of all charges.