Lithium ferrites are widely used in microwave technique. Usually, such ferrites are prepared by the conventional ceramic double sintering method in which solid state reactions between oxides and/or carbonates are carried out in the first stage. The microstructure of synthesized ferrite powders has a significant effect on the properties of ferrite ceramics obtained as a result of sintering in the second stage. In order to achieve the necessary microstructure properties of ferrites, additional technological operations are used, for example, a mechanical milling in a planetary mill. This type of treatment allows homogenizing, grinding and mechanically activating the initial powder reactants, which leads to a stimulation of physic-chemical processes during synthesis of ferrites [1-2]. In this work, the effect of ball milling of synthesized LiFe5O8 ferrite powders on the microstructure of ferrite ceramics was studied by laser diffraction (Fritsch Analysette 22 MicroTec Plus), XRD (ARL X’TRA) and SEM (Hitachi TM-3000) analysis. The mechanical milling of LiFe5O8 was carried out in a Fritsch Pulverisette 7 or AGO planetary mills at room temperature using the zirconium or steel grinding bowls and balls. The process of ferrite sintering was investigated using dilatometric analysis (DIL 402 C, Netzsch). The structural disordering was estimated by TG/DSC analysis (STA 449 C Jupiter, Netzsch). The results showed a strong difference in the structure of ferrite ceramics obtained from ferrite powder pre-milled by dry and wet milling. Thus, dry milling via steel balls results in slight decrease in particle size of the ferrite powder, which has a narrow monomodal particle distribution. The ferrite ceramics, obtained from this powder, is characterized by the presence of an ordered αLiFe5O8 phase. On the contrary, wet milling in isopropyl alcohol leads to a formation of ultrafine ferrite powder, from which the ceramics was obtained that is characterized by a well-developed fine-grained polycrystalline structure and the main presence of a disordered β-LiFe5O8 phase. It was shown that a relatively high density and low porosity were observed for such ceramics, which is practically impossible to obtain for pure lithium ferrite without the use of impurities that affect the ferrite sintering processes. It was established that during mechanical milling in a planetary mill with zirconium balls, a ferrite powder is strongly contaminated with a zirconia material, resulting in formation of LiFe5O8/ZrO2 composite ceramic.