Urban poverty and floods are the foremost challenges for coastal cities of Southeast Asia. It is often assumed that the poor residents of a floodaffected area are mainly vulnerable. Yet, only few studies have placed flood-experienced people at the center of the vulnerability assessment. This chapter aims to explore who is vulnerable among the flood-affected urban poor and how they define flood-related vulnerability. We found that kampung residents use their flood experiences as a stock of knowledge to differentiate the level of vulnerability. Therefore, we suggest applying a life-world analysis to assess the state of vulnerability of an informal urban settlement and expect to identify the potentiality of the flood-experienced ones to organize transformative adaptation.