This paper presents vulnerability maps for reinforced concrete moment frames (RCMFs) in Mexico City's Metropolitan Area (MCMA) for a _Ms=8.1 earthquake scenario assessing peak nonlinear dynamic responses using the concept of displacement ductility demand spectra (DDDS). The considered earthquake scenario is the 1985 Michoacán Earthquake. Artificial and recorded ground motions were used. Takeda model was used to simulate nonlinear behavior of RCMFs. Seismic strength for existing RCMFs structures was estimated according to the nominal strength required by versions of Mexico's Federal District Code (MFDC) that were effective before the 1985 earthquake. Overstrength sources for RCMFs were also evaluated. With all of this information, DDDS were obtained for different sites in MCMA. Later, vulnerability maps based on contours of equal displacement ductility demands and nonlinear displacements for a given structural period and a version of MFDC were defined. These vulnerability maps were compared with the geographic area of severe structural damage and collapses mapped during the 1985 earthquake. Based on the results of this study, it is believed that this procedure can be useful to forecast demands for different structural systems for a given earthquake scenario, being therefore potentially useful for urban planning of cities located in zones of high seismic risk.