Structural features of nanocomposite YCu powder material obtained by mechanical alloying of the equiatomic Y-Cu elemental powder mixture in a high-energy ball mill have been characterized by X-ray diffraction, and scanning electron microscopy. It has been shown that YCu compound with a full ordered CsCl-type structure along with YCu2 intermetallic have formed at early stage of the milling process (10 min) while a long-time processing product contains these phases as well as Y2O3 oxide. The nanoindentation measurements of the bulk samples compacted after 60 and 120 min of milling have revealed that the mean hardness values H for these samples are higher than those for conventional bulk YCu intermetallic obtained by arc melting. The main reasons for hardness increase are fine-grained microstructure and reinforcement of material by Y2O3 particles uniformly distributed throughout the volume. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.