The effect of iron deficiency on the structural, electrical and magnetic properties of the nano PbFe12-xO19-delta (where x = 0.0, 0.25, 0.50, 0.75 and 1.0) hexaferrites prepared by sol-gel auto combustion and further processed by microwaves is presented. The structure studied using transmission electron microscope (TEM) showed hexagonal cylindrical particles with an average size of similar to 20 nm. Selected area electron diffraction (SAED) reflected highly crystalline nature of these nanoparticles. From the dielectric characterizations ac-conductivity, dielectric constant and loss tangent are analysed for pure and modified PbFe12-xO19-delta hexaferrites. The magnetic analysis revealed the formation of single-domain structure. Saturation magnetization (M-s) decreases from 63.2 (x = 0) to 38.2 (x = 1.0) emu/g with increasing the Fe ions deficiency. Room temperature Mossbauer spectra show five sextets for all compositions confirmed the single phase formation. The relative area of 12k (up arrow) site decreases and 4f(2 )(down arrow) increases drastically with increasing the Fe ions deficiency in Pb-hexaferrites.