Mn–Zn ferrites doped with different contents of Y 3+ ions were prepared by conventional two-step synthesis method. The microstructure and electromagnetic properties of the as-prepared Mn–Zn ferrites were investigated. It was found that all the samples consisted of ferrite phases of typical spinel cubic structure, and when Y 3+ ion content was upto 1.5 mol%, yttriumirongarnet (Y 3Fe 5O 12) phase with garnet structure was detected. With increasing doping content of Y 3+ ions, the lattice constant and grain size increased, and after an increase to its maximum value, the sample apparent and relative densities dropped down. Through the analysis of magnetic properties, it was revealed that the saturation magnetization, and both the real and imaginary parts of permeability of the as-prepared samples raised with increasing doping content of Y 3+ ions but decreased with more Y 3+ ions, while their coercivity showed an opposite change trend; and the Curie temperature increased monotonously. The measurement of dielectric properties indicated that the dielectric constant of the doped Mn–Zn ferrites presented a rise with increasing Y 3+ ion content, and dropped down gradually when more Y 3+ ions were doped, while the dielectric loss tangent would decrease with Y 3+ content upto 1.5 mol%, but after that, it increased.