The 78AgI, 16.5Ag 2 O, and 5.5B 2 O 3 mol% powder mixture, ultra-fast quenched 78AgI-16.5Ag 2 O-5.5B 2 O 3 glass containing α-AgI crystalline precipitates and pristine AgI were ball-milled at a high rotation speed. For all the materials, the processing did not cause formation of α-AgI phase, in contrary, it prompted α to β phase transition of the α-AgI precipitates in the glass. Nanosize scale β/γ-AgI grains were detected both in the milled powder mixture and in the glass but not in the pristine AgI powder.The decrease of α to β phase transition temperature was observed for the milled materials during cooling from 170°C, ca. 10°C, 60°C and 75°C respectively for the AgI powder, the powder mixture and the glass. Stabilization of the α-AgI to low temperatures was related to the nanosize scale β/γ-AgI grains. The work demonstrates, that although it is not possible to stabilize α-AgI in pure silver iodide powder by ball-milling, nevertheless it is achievable for mixtures with high AgI contents.