Coarse grain growth has conventionally been induced by high temperature and pressure during the sintering of ZrC ceramic. Even under the harsh sintering conditions, the microstructure contained inhomogeneous grain sizes and residual pores. To reduce the agglomeration of grains during sintering, we focused on inducing lattice strain. Mechanical milling was carried out to induce high strain in the lattice of ZrC, with the amount of strain varying during milling. This could slow down the grain growth, eventually producing homogeneous grain sizes of sintered ZrC ceramic. The sintered grain size decreased at the maximum strain, with 10 h of milling, while it started to increase significantly after 10 h. This study demonstrates that the sintering conditions could be optimized to obtain the lattice strain for fully dense sintered ceramic.