In this work, attempt is made to prepare and study the phase evolution of nanocrystalline Pb(Zr0.53Ti0.47)O-3 powder with both planetary and high energy shaker mill in air atmosphere, using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Three different series of samples with various processing conditions i.e., ball to powder weight ratio (BPR) of 10/1. 20/1 at 500 rpm and 10/1 ratio at 250 rpm, were prepared using a planetary mill. Further, another series of samples were also prepared using a high energy shaker mill with BPR = 10 at 900 rpm. The BPR was seen to have a marked effect on the phase formation of PZT nanocrystalline powder. While the formation of some nanocrystalline intermediate phases of wide compositional distribution in an amorphous matrix was confirmed for the samples prepared using planetary mill with BPR = 10 at 250 and 500 rpm, single phase PZT could be formed when prepared at BPR = 20 at 500 rpm. Further, it was also shown that the formation of single phase PZT nanocrystalline powder of an average crystallite size of 10 nm could take place after only 30 h of milling when activated by shaker mill with BPR 10 at 900 rpm. The results obtained are related to the rate of the injected energy and diffusion processes taken place. (C) 2004 Kluwer Academic Publishers.