We report synthesis and crystalline structure study of the Sm2FeMnO6 new complex perovskite, by X-ray diffraction experiments and through the application of Rietveld refinement. Results revealed the crystallization of system in a structure given by Pmn21 (#31) space group and lattice parameters a ¼ 7.621(1)A ˚ , b ¼ 5.675(3)A ˚ and c ¼ 5.378(3)A ˚ . Ab initio calculations of density of states (DOS) and electronic structure were carried out for this perovskite-like system by the density functional theory (DFT) and using the full-potential linearized augmented plane waves (FP-LAPW) method. All calculations were carried out using spin polarization. Material evidences a conductor-like character, predominantly due to d–xy Fe orbital of the spin down channel. Magnetic response of system has contributions of Fe and Mn spin up orientation. The calculated magnetic moment in cell was 34.48 mB and the magnetic moment in interstitial was 1.54 mB.