The ordering temperaturesTc1(disordered &bgr; toB2order) andTc2(B2toL21order) have been obtained in Cu–Al–Ni shape memory alloys with different concentrations by electrical resistivity. The dependence of the ordering temperatures on the concentration has been established. Also, a modification of the theoretical calculations has been proposed to predict the ordering temperatures in Cu–Al–Ni ternary alloys. A good agreement between the theoretical ordering temperatures and the experimental results has been found. ©1997 American Institute of Physics.