Present study aims to correlate phase evolution and magnetic properties of Cu-Ni-Co-Fe alloys synthesized by ball milling and isothermal annealing of the ball milled products. Variation of magnetic properties of different alloys has been studied in respect of the chemistry, microstructural constitution and defect concentration. It is observed that in the present Cu-base alloys, stacking/twin fault probabilities are order of magnitude lower than that obtained by ball milling of the elemental constituents (Cu and Co) and hence, their contribution to the magnetic properties is insignificant. It is shown that chemistry of the alloys and size of the constituent phases determined the magnetic behaviour of the alloys. Precipitation of hard magnetic Co in the non-magnetic Cu-matrix has contributed most significantly to the improvement in magnetic properties. (C) 2009 Elsevier B.V. All rights reserved.