Nanoparticles of (Zr0.8Sn0.2)TiO4 (ZST) ceramics were prepared by ball milling. Different concentrations of (1, 2 and 3 wt%) nanoparticles of size about 60 nm were introduced into the sub micron-sized (0.8 μm) powder of the ZST ceramics to study the effect of their inclusion on densification, microstructure, and microwave dielectric properties of the ZST ceramics. It is found that the addition of nanoparticles to the ZST ceramics significantly improved the density with reduction in sintering temperature. In the present case, it is believed that the surface energy of fine powders and their defect energy are the driving force for sintering and increase in uniform grain size, which are activated at the sintering temperature. The microwave dielectric properties of ZST ceramics were also heavily influenced by the addition of nanoparticles of ZST. The maximum dielectric constant of 39.2 and Q × fo value of 72 900 were found to be for the samples added with 2 wt% of the nanoparticles and sintered at 1300°C for 3 h. However, it is observed that samples made with nanopowder alone exhibited poor sinterability.