The objective of the present work is to evaluate half metallicity and spin dependent transport properties of iron doped CdSe and cobalt doped CdSe compounds. The spin-polarized band structures (semiconductor in one spin state and conductor in the other spin state) predict that Cd0.875Fe 0.125Se and Cd0.875Co0.125Se are half metals. The calculated crystal filed splitting energy show larger energy gap between eg and t2g for Fe than Co doped CdSe compound. Furthermore, magnetization, exchange coupling and band-gap increase with decrease in the lattice constant. Overall, Cd0.875Fe 0.125Se and Cd0.875Co0.125Se in the zinc-blend phase show half-metallic ferromagnetic nature and are expected to be potential materials for spintronic devices. © 2011 Elsevier B.V. All rights reserved.