This paper describes urban flood vulnerability using a vulnerability index which consists of four vulnerability issues encompassing social, economic, environmental and physical issues. The study was carried out by selecting variables affecting the flood vulnerability, collecting and analyzing corresponding data, developing equations for computing the flood vulnerability indices, and calculating the corresponding indices. Comparison of the flood vulnerability was made using data from three cities, namely, Hat Yai, Chiang Mai and Ubon Ratchathani. The results showed that the cities ranged from highest to lowest flood vulnerability were Chiang Mai, Hat Yai, and Ubon Ratchathani. In addition, Chiang Mai is considered to be the most vulnerable to social and environmental issues while Hat Yai is most vulnerable to the economic issues and Ubon Ratchathani is most vulnerable to the physical issue. [ABSTRACT FROM AUTHOR]