Iron-doped ZnSe (Fe:ZnSe) single crystals were grown by the traveling heater method with the accelerated crucible rotation technique (ACRT) using SnSe as a solvent. The as-grown Fe:ZnSe single crystals were characterized by XRD, Raman, XPS, IR transmission imaging microscope, and the X-ray rocking curve. The results show two kinds of inclusions existing in Fe:ZnSe crystals, i.e. solvent SnSe inclusions, and hexagonal ZnSe inclusions with a wurtzite structure. The inclusions with sizes ranging from 30 to 150 μm were homogeneous distributed with a total concentration of only 2.68 × 102 cm−2. The full width at half-maximum (FWHM) of X-ray rocking curve on (220) diffraction planes was 38 arcsec and the average infrared transmittance exceeded 70%. Furthermore, it was confirmed that the iron ions were successfully incorporated into ZnSe lattice without degrading the crystalline quality, and the bivalence was dominant for iron atoms in Fe:ZnSe crystals, meaning that they are suitable for developing mid-infrared (3–5 μm) gain medium applications.