Transmission electron microscopy (TEM) investigations of the early stages of precipitation of a b.c.c. phase in f.c.c. matrix have been carried out in a dilute Cu–Cr–Zr alloy. The initial product of decomposition, characterized by a state of order, which mimics a cube-on-cube orientation relationship (OR) with the matrix appears prior to ordered b.c.c. phase precipitates showing Nishiyama– Wassermann (N–W) OR.