In the present study we report the effect of K doping on the structural, magnetic and magnetocaloric properties in La0.8Ag0.2-xKxMnO3 (0 <= x <= 0.15) powder samples synthesized using the solid state reaction method at high temperature. X-ray diffraction analysis using Rietveld refinement show that all our samples crystallize in the rhombohedral structure with R (3) over barc space group. The surface morphology and elemental analysis of both samples were carried out by scanning electron microscopy (SEM) and energy dispersive X-ray technique (EDX), respectively. Magnetization measurements versus temperature in a magnetic applied field of 50 mT showed that all our investigated samples display a paramagnetic-ferromagnetic transition with decreasing temperature. The Curie temperature T-C increases with increasing K content from 278.5 K for x = 0-330 K for x = 0.15.A large magnetic entropy change vertical bar Delta S-M vertical bar I. deduced from isothermal magnetization curves, has been observed in our samples with a peak centered around their respective T-C. The maximum of the magnetic entropy change vertical bar Delta S-M(Max)vertical bar in a magnetic field change of 5T is found to be 6.12, 5.28, 4.92 and 4.26 J kg(-1) K-1 for x = 0, 0.05, 0.1 and 0.15 respectively. Large relative cooling power (RCP) value of 258.3 J kg(-1) is obtained for La0.8Ag0.05K0.15MnO3 sample, at a field change of 5T. This relatively large value associated to a Curie temperature of 330 K make the present compound a promising candidate formagneticrefrigerators around room temperature. (C) 2011 Elsevier B.V. All rights reserved.