The limited experimental information regarding the seismic performance of repaired reinforced concrete (RC) structures has been a technical challenge to assess the performance of repaired buildings after strong earthquakes. The main objective of this research is to evaluate the seismic performance of RC walls repaired by increasing the thickness and shear strength. Two RC walls with unconfined boundaries and aspect ratios of 1.75 and 2.5 were built. The walls were subjected to an axial load ratio of 0.1 and a pseudo-static lateral displacement protocol until failure. The damaged walls were repaired by adding additional web reinforcement and increasing the thickness. The bars that suffered buckling or fracture in the first tests were replaced with the new bars that were spliced with mechanical couplers. The repaired walls were tested with the same loading protocols like the one used in the first tests. The seismic capacity of the repaired walls is analyzed in terms of the maximum strength, deformation capacity, dissipated energy, and ductility. The test results showed that the repaired walls presented enhancement in the maximum strength and dissipated energy. Additionally, the failure mode of the repaired walls was different from that of the original walls. The obtained results from the reported tests are expected to be used to improve analytical methods to predict the seismic behavior of repaired walls.