Abstract In this work, K 2 Bi 8 Se 13 material was ball-milled in order to develop nanostructures through the modification of structural features. Structural changes during ball-milling were followed by powder X-ray diffraction measurements, Scanning Electron Microscope images and High Resolution and conventional Transmission Electron Microscopy studies. Powder X-ray diffraction patterns presented a significant broadening in the peak patterns with the increase of the ball-milling time that was attributed to the formation of nanocrystalline as well as amorphous material. TEM studies showed the formation of K 2 Bi 8 Se 13 nanostructured material consisting of nanocrystals that were surrounded by an amorphous matrix. Preliminary measurements of thermoelectric properties have shown that Seebeck coefficient is increased in ball-milled samples where as thermal conductivity is decreased. Sintering process that was applied on the ball-milled material leads to its recrystallization and the growth of grains.