Magnetic nano-particles (MNPs) of CoFe have been doped in poly(2-methoxy, 5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) to investigate the effects on hole transport. Introduction of CoFe MNPs in MEH-PPV increases the trap concentration and reduces the hole current. Under the simultaneous application of magnetic and electric fields, the spin of CoFe MNPs is aligned, which results into the shift of Fermi level of CoFe MNPs towards highest occupied molecular orbital (HOMO) of MEH-PPV and spin polarized holes are transferred to MEH-PPV. Transport of spin polarized hole has been studied at different temperatures. Application of magnetic field resulted into substantial increment in the hole current at low voltages that became independent of temperature at low temperatures. At high voltages current has been found to be governed by the trap controlled power law with exponential distribution of traps in energy space. (C) 2012 Elsevier Ltd. All rights reserved..