We report structural, morphological (particle size, shape) and magnetic properties of nanosized Ni0.5Zn0.5Fe2O4 prepared by high-energy ball milling. We have employed XRD, HRTEM and Mossbauer spectroscopic techniques to achieve the goal. Sample exhibits superparamagnetic behaviour at room temperature. At 21 K the ferrimagnetic ordering and collective excitation along with a strong super-paramagnetic contribution give rise to a mixed magnetic phase.