Operation of cement industry with large number of non linear load has an impact on the power quality at the connected electric network. Harmonic distortion is one of the most important phenomena, which affects the plant distribution network as well as grid performance. This paper provides an in depth discussion on harmonic distortion taking place in the cement plant power system. A case study, to determine where a significant amount of harmonic currents or voltages exists in the system is performed using power quality analyzer. From these measurements and subsequent calculations, the impact of harmonics is analyzed. It is found that the harmonic distortion is invariably present with in the distribution system of the plant as well as in the grid side