Nanocrystalline Ni-Zn ferrite was synthesized at room temperature by high energy ball milling. Crystallographic phases appearing during ball milling & crystallite sizes were determined from X-ray diffraction (XRD) analysis. The magnetic response of the powder samples were investigated using vibrating sample magnetometer (VSM) which showed 30hr milled un annealed sample to be superparamagnetic. © 2012 American Institute of Physics.