Performance-based earthquake engineering necessitates the development of reliable nonlinear analysis models that are able to simulate the behavior of structures from the onset of damage through collapse. These models provide engineering demand parameters that are then related with damage measures and describe the damage of a building and its components. To accurately simulate dynamic response up to collapse of structures, it is important to model strength and stiffness deterioration of structural components in addition to P-Δ effects. These models require the use of large sets of experimental data for calibration of their deterioration parameters. This paper discusses the development of three databases on experimental data of steel W-beams, tubular hollow square steel columns, and RC beams. These databases are used for quantification of important parameters that affect the cyclic moment-rotation relationship at plastic hinge regions in steel and RC components. Emphasis is placed on the prediction of collapse of buildings caused by earthquakes. The utilization and importance of the three databases in the context of performance-based earthquake engineering is demonstrated through a case study of a 4-story steel building. Its seismic performance is successfully assessed through collapse. © 2013 American Society of Civil Engineers.