Systematic measurements pertinent to the magnetocaloric effect and nature of magnetic transition around the transition temperature are performed in the 10 nm Pr 0.5Ca 0.5MnO 3 nanoparticles (PCMO10). Maxwells relation is employed to estimate the change in magnetic entropy. At Curie temperature (T C) ∼ 83.5 K, the change in magnetic entropy (-ΔS M) discloses a typical variation with a value 0.57 J/kg K, and is found to be magnetic field dependent. From the area under the curve (ΔS vs T), the refrigeration capacity is calculated at T C ∼ 83.5 K and it is found to be 7.01 J/kg. Arrott plots infer that due to the competition between the ferromagnetic and anti-ferromagnetic interactions, the magnetic phase transition in PCMO10 is broadly spread over both in temperature as well as magnetic field coordinates. Upon tuning the particle size, size distribution, morphology, and relative fraction of magnetic phases, it may be possible to enhance the magnetocalorific effect further in PCMO10. © 2012 American Institute of Physics.