The aim of this study is to evaluate the seismic performance and calculate the fragility of self-centering structures under mainshock and mainshock–aftershock sequences. For this purpose, two three- and nine-story structures were designed based on available references in the field of self-centering structures and then modeled nonlinearly in Perform software. Twenty mainshock records along with aftershocks were selected and applied to the structures through nonlinear dynamic analysis. Finally, various performance evaluation parameters of the structures, such as roof horizontal displacement, distribution of dissipated strain energy in the structure due to the mainshock and aftershock, and rocking displacement under both cases were investigated. Subsequently, incremental dynamic analysis (IDA) curves and fragility curves were calculated and presented. The fragility results indicate that, firstly, the fragility of shorter structures (three-story) is greater than that of taller ones (nine-story). Secondly, the fragility values for aftershock and mainshock at different performance levels are close to each other with only slight differences. For example, in the three-story structure at the LS performance level and maximum PGA = 1.8g, the probability of exceedance in the mainshock-only case was calculated as 0.87, while in the mainshock–aftershock case it was 0.93. In the nine-story structure at the LS performance level under the same maximum acceleration, the probability of exceedance in the mainshock-only case was 0.78, and in the mainshock–aftershock case it was 0.88.