[en] The effect of mechanical milling in a planetary ball mills on dispersity of the synthesized lithium ferrite powder was investigated by laser diffraction technique. The mechanical milling of powder was carried out by two planetary ball mills: SPEX 8000M and Fritsch Pulverisette 5 with different time period. The lithium ferrite powder was milled for 30, 60 and 120 minutes in the first ball mill. The powder milled for 60 minutes in the second ball mill was performed. The results showed that an increase in the milling time slightly decreases the average particle size of the ferrite powder in case both ball mills. However, only milling in a SPEX planetary mill increases homogeneity of the ferrite powder, while the milling in Fritsch causes intensive processes of particle aggregation. (paper)