The literature on urban resilience assessment has grown rapidly over the past two decades. This paper aims to provide a better understanding of the state of knowledge on urban resilience assessment through mapping the knowledge domain and highlighting emerging trends during different periods. The objects of study were 420 papers published in the Web of Science from 1998 to 2020. Science mapping was done using VOSviewer and CiteSpace, two widely known software tools for bibliometrics analysis and scientometric visualization. The results show that research published on urban resilience assessment was very limited and fragmented until 2009, and the focus has mainly been on risk mitigation and vulnerability assessment. The intellectual base grew between 2010 and 2014, when a paradigm shift from approaches based on robustness and reliability toward more adaptation-oriented approaches occurred. Finally, the annual publication trends have grown rapidly over the past five years and there has been more emphasis on climate change adaptation and flood resilience. Overall, in terms of dimensional focus, more attention has been paid to infrastructural, institutional, and environmental aspects at the expense of social and economic dimensions. In addition to information on thematic focus and evolution, this paper also provides other bibliometrics information on the influential authors, institutions, journals, and publications that lay the foundation of the field and can be used by various interested groups as points of reference to gain better knowledge about the structure and thematic evolution of urban resilience assessment. The paper concludes by highlighting gaps and making some recommendations for future improvement of the field. Major gaps are related to assessing resilience against socio-economic and health risks (e.g., economic recession and pandemics such as COVID-19).