The interior joint shear strength of nonductile frames strengthened with reinforced concrete (RC) jackets, but with no new joint shear hoops and no dowel anchors installed into the new and old concrete interface, was investigated experimentally. Seven one-way interior beam-column joint subassemblages were tested under quasistatic cyclic loading to observe the joint shear strength and overall frame performance. The test measurements are also used to verify two of the analytical models used for predicting the horizontal shear strength of jacketed joints without horizontal joint shear reinforcement. The results show that the RC jacketed scheme is able to efficiently rehabilitate nonductile frames with very poor joint details. An empirical equation for calculating the joint shear strength of RC jacketed frames is proposed in this study.