The annealing behavior of Cu‐8.5 at.% Ge filings has been studied by means of x‐ray diffraction. The shifts in the positions of the powder pattern peaks from deformed and partially annealed samples can be accounted for by stacking faults and changes in the layer spacings at the stacking faults. No evidence was found for extrinsic faulting. Isothermal annealing treatments in the range 180°–240°C showed that the deformation stacking faults annealed out in a two‐stage process. The first stage was associated with recovery while a kinetic study showed the second stage to be connected with recrystallization. The rms microstrains obtained by Fourier analysis techniques annealed out in a manner similar to the stacking faults. The particle size as determined by Fourier analysis remained constant during isothermal annealing until the recrystallization stage where it increased sharply. Analysis of the peak asymmetries during annealing showed that the number of twin faults remained constant at the value for the cold‐worked state until the recrystallization stage where a small increase occurred followed by a rapid decrease toward zero.