Reinforced concrete buildings are frequently exposed to seismic loadings. This condition generates either uniaxial or biaxial unbalanced moment on slab-to-column connections. The design of such connections varies greatly between most international codes. This paper investigates the effect of the unbalanced moment on the punching shear strength of two-way interior slab-to-column connections. For this purpose, a nonlinear finite element analysis using ANSYS-V19.2 software package was performed. Thirteen High-Performance Concrete (HPC) slabs with different eccentricities were analyzed. During this context, a number of three large scale specimens made of HPC were firstly tested experimentally to validate the used model. The interaction diagram between the unbalanced moment and the punching shear strength was developed and then compared against those resulted by different international codes (ACI 318-19, CSA A23.3-04, EC2-04, BS8110-97, and ECP 203-2018). The results showed that by increasing the unbalanced moment, the punching shear strength is significantly decreased and the failed surface from the column face is pulled toward the column. Moreover, the normalized moment-shear relationship showed a linear interaction diagram.