The outbreaks of severe acute respiratory syndrome (SARS) that unfolded at various locations throughout the world represented the first collective threat to public health that was amplified by the processes and structures of our contemporary globalized society – such as, the compression of time and space and increased linkages between various cities of the world. In this article, the global outbreak of SARS in 2003 is used as an empirical referent to discuss the implications of infectious disease spread among and within cities under the conditions of globalization. To capture the uniquely dynamic qualities associated with infectious disease outbreaks under globalizing conditions, we suggest that conventional accounts of the spatial diffusion of pathogens incorporate topological principles that are sensitive to such properties as: fluidity, flows, mobility and networks, that now play a critical role in disease diffusion.