Understanding the pattern of past and present deformation at depth provides a valuable key for enhancing our knowledge about the evolution of the collisional boundary in the Iran region. Here we use measurements of seismic anisotropy to understand this pattern. We use data from a temporary seismic network in western Iran to calculate shear-wave splitting parameters. The network was in operation for one year in 2013 and 2014 and consisted of 63 broadband seismometers installed along three parallel profiles that crossed the western Zagros Mountains, central Iran and the western Alborz Mountains. We present our results as splitting measurements of the teleseismic SKS/SKKS core-refracted phases. Our results show an average delay time of about 1.3 sec. The fast polarization orientation of the measurements varies significantly along the profile, indicating important changes in style of deformation across different tectonic units. A range-parallel trend is observed in the Zagros, while the orientations of the fast axes are perpendicular to the strike in the Alborz.