In this study, we developed a new ground‐motion model (GMM) for the 5% damped horizontal spectral accelerations using a newly developed database of strong‐motion records for Iran. The newly developed GMM includes peak ground acceleration and 5% damped elastic pseudospectral acceleration ordinates of . We used a database containing 1356 records from 208 events up to 2013, with the moment magnitude range of , and the rupture distances or closest distance to the rupture plane up to 400 km. The selected database includes a variety of fault mechanisms, for example, strike slip, normal, and reverse. We used Akaike and Bayesian information to determine the validity of the chosen regression model. We introduced random‐effect coefficients in our mixed‐effect regression model to capture the regional variations among Zagros, Alborz–Azarbaijan, Kope Dagh, and central east Iran and found no statistical variations among these regions. As part of the developed GMMs, we included the nonlinear site effect using (average shear‐wave velocity in the upper 30 m of soil profile). Distribution of residuals obtained considering between‐event, site‐to‐site, and event‐station showed no discernable trends for the developed GMM. Furthermore, our proposed model is compared with Kale et al. (2015), which has been a recent and well‐established new generation model for Iran and Turkey.