The seismic vulnerability of buildings located in Pisco, Peru, was studied using damage survey data and seismic ground motion simulation. Inventory and damage information for more than 10,000 buildings was registered in survey data compiled by CISMID at Peru’s National University of Engineering. The soil classes in the Pisco district were classified into three zones based on the predominant periods of microtremors at 85 sites, and damage ratios were calculated for each zone. Surface ground motions in each zone were estimated on the basis of base-rock motion simulation and shallow soil-column response analysis. Finally, fragility curves for adobe and brickmasonry buildings were derived in terms of PGA and PGV. The results were compared with fragility functions developed in other studies.