W-Cu composite powders were prepared by high energy milling under two milling environments: cyclohexane and air. Composite particles are formed in both cases. The W particles are fragmented and embedded into the Cu particles. Both, W and Cu, are heavily strained, mainly in the first hours of milling. The composite powder has high homogeneity and is much finer than the original Cu powder. The mean particle size of the powders milled in both conditions is very close, but the wet milling was near 25% longer than dry milling and the size distribution is wider. This is consequence of the higher milling intensity of dry milling.