Single-phase diluted magnetic systems Zn_(1-x)Fe_xO have been prepared by chemical route. Structural and spectroscopic(UV–Vis and Mssbauer) studies indicate the incorporation of Fe~(3+) ions in the lattice sites. The UV–Vis results point to a systematic increase in the band gap with increasing Fe doping. The room temperature magnetization of Zn_(1-x)Fe_xO indicates a paramagnetic behavior which is in accordance with the Mssbauer results, illustrating quadrupolar doublet. At low temperature, the zero-field-cooled(ZFC) magnetization shows a cusp and this temperature increases systematically with decreasing particle size. The weak exchange bias effect manifested by a M–H loop shift is observed for x = 0.03. This shift is accompanied by the enhancement of coercivity. The dc magnetization results suggest the coexistence of ferromagnetic and antiferromagnetic exchange interactions for low doping of Fe, i.e., for x = 0.03. Structural and spectroscopic (UV-Vis and Mssbauer) studies indicate the incorporation of Fe ~ (3+) ions in the lattice sites. The Single-phase diluted magnetic systems Zn_ (1-x) Fe_xO have been prepared by chemical route. UV-Vis results point to a systematic increase in the band gap with increasing Fe doping. The room temperature magnetization of Zn - (1-x) Fe_xO indicates a paramagnetic behavior which is in accordance with the Mssbauer results, illustrating quadrupolar doublet. At low temperature, the zero-field-cooled (ZFC) magnetization shows a cusp and this temperature increases systematically with decreasing particle size. The weak exchange bias effect manifested by a M-H loop shift is observed for x = 0.03. by the enhancement of coercivity. The dc magnetization results suggest the coexistence of ferromagnetic and antiferromagnetic exchange interactions for low doping of Fe, ie, for x = 0.03.