In this work a new approach to grind polymer ion exchange particles smaller than one micrometer at ambient conditions is presented. Detailed studies have been performed on the grinding of commercial available porous polymer ion exchange particles with a median size of several hundred micrometers. The results have shown that it is possible to grind porous polymers in a stirred media mill down to several hundred nanometers. The ion exchange capacity of the particles remains unaffected during the grinding process.