The objective of this paper is to describe on-going research on the seismic hazard analysis and vulnerability assessment for the Montreal Urban Community. The first part describes the overall work being performed in developing an inventory of critical lifelines and the estimation of their seismic vulnerability. The second part describes a procedure and the results for a seismic microzonation of site effects that combine both a field approach based on ground-ambient noise analysis and numerical modeling based on one-dimensional SHAKE computations.