This research was aimed to synthesize calcium carbonate nanoparticles from CaCl2 and Na2CO3 precursors by mechano-chemical route without any subsequent heat treatment of the as-milled powder. The powder mixture was once milled in a planetary ball mill with NaCl as the diluting agent and another time with KCl. CaCO3 nanoparticles were achieved after 10 min of continuous milling in the planetary ball mill. CaCO3 nanoparticles were also fully formed after 10 min of continuous milling by using an attrition mill. The resulting powders milled via both milling methods were analyzed to investigate the effect of the diluting agent and milling method on particle size of CaCO3. BET results calculated the specific surface area of CaCO3 nanoparticles to be 19.27 m(2) g(-1). Furthermore, TEM results substantiated the fact that particle size ranges from 60 to 90 nm. (C) 2011 Elsevier B.V. All rights reserved.