The effect of ball milling on microstructural change of (Ti,W)C solid solution was investigated. In addition to the particle size reduction with milling time, detailed studies using the X-ray diffraction line profiles were carried out to evaluate the microstructural parameters, including lattice parameter, crystallite size and microstrain. Nelson Riley extrapolation and Williamson-Hall method are employed. The results suggest lattice expansion, with the lattice parameter increasing from 43212 A to 43241 A. The defects and surface stress generated during ball milling are deemed to be responsible for the increased d-spacing of (Ti,W)C solid solution with milling time. The crystallite size displays a diminishing trend with increasing milling time, which is consistent with the SEM observation. However, the microstrain developed is tensile in nature and firstly increases with up to 36 h milling, and then the strain reduces for further milling perhaps due to the strain relaxation by the formation of dislocations. (C) 2017 Elsevier Ltd. All rights reserved.