We present here a comparative study on Structural and magnetic properties of bulk and thin films of Mg0.95Mn0.05Fe2O4 ferrite deposited on two different substrates using X-ray diffraction (XRD) and dc magnetization measurements. XRD pattern indicates that the bulk sample and their thin films exhibit a polycrystalline single phase Cubic spinel structure. It is found that the film deposited on indium till oxide coated glass (ITO) substrate has smaller grain size than the film deposited on platinum coated silicon (Pt-Si) Substrate. Study of magnetization hysteresis loop measurements infer that the bulk sample of Mg0.95Mn0.05Fe2O4 and its thin film deposited on Pt-Si substrate shows a well-defined hysteresis loop at room temperature, which reflects its ferrimagnetic behavior. However, the film deposited on ITO does not show any hysteresis, which reflects its superparamagnetic behavior at room temperature. (C) 2008 Elsevier B.V. All rights reserved.