Seismic microzonation involves generation of seismic hazard maps with respect to estimated ground motion characteristics on engineering bedrock outcrop based on a regional seismic hazard study compatible with the scale of the microzonation. A grid system is implemented dividing the investigation area into cells according to the availability of geological, geophysical and geotechnical data. Site characterizations are performed based on available borings and other relevant information by defining representative soil profiles for each cell with shear wave velocities extending down to the engineering bedrock. 1D site response analyses are conducted to estimate site specific earthquake ground motion characteristics on the ground surface for each representative soil profile to estimate elastic response spectrum based on calculated acceleration time histories. Average of spectral accelerations between 0.1 and 1 s periods of elastic acceleration response spectrum are calculated as one of the two parameters representing earthquake shaking intensity on the ground surface. Site specific peak spectral accelerations corresponding to 0.2 s period are also calculated as the second microzonation parameter using the empirical amplification relationships proposed by Borcherdt (1994) based on equivalent shear wave velocities for the top 30 m of the soil profiles. Superposition of these two parameters is assumed to represent overall effect of site conditions and is adopted as the criteria for the microzonation with respect to ground shaking intensity. Recently, an extensive site investigation study was carried out on the European side of Istanbul as the first phase of the large-scale microzonation project for the Istanbul Metropolitan Municipality. A detailed microzonation with respect to earthquake ground shaking intensity is carried out for the Zeytinburnu town in Istanbul using part of these recently compiled soil data and the regional probabilistic seismic hazard scenario proposed by Erdik et al. (2004). The microzonation maps are compared with the previously generated Zeytinburnu microzonation maps for the European Union Framework FP6 LessLoss Project (Ansal et al., 2007a) and for the Zeytinburnu Pilot Microzonation Project (Ansal et al., 2005; Kilic et al., 2006; Ozaydin et al., 2004) where microzonation maps were produced with limited number of site investigations and site response analyses using more approximate microzonation procedures.