Polymer-piezoceramic composites harness the flexibility of polymer and piezoelectric properties of ceramics to offer flexible piezoelectric materials for use in energy harvesting applications. Although, there is a general temptation to use piezoceramics which exhibits high piezoelectric coefficient (d(33)) in the fabrication of such composites, there are limitations posed by the processing conditions of the composite which eventually determines their overall performance. In the present work we have explored this aspect in detail. We fabricated composites with polyvinylidene fluoride (PVDF) as the polymer and three different piezoceramic powders namely BaTiO3(BT), Ba(Ti0.97Sn0.03)O-3(BTS) and Sm-doped Pb (Mg1/3Nb2/3)O-3-PbTiO3(Sm-PMN-PT). Our focus here is to understand the role of grain size of the ceramic powders in determining the dielectric, piezoelectric, and energy harvesting performance of the composites. To broaden the perspective, the results are compared with another analogous composite 0.59PbTiO(3)-0.41Bi(Zr0.5Ni0.5)O-3(PT-BNZ)-PVDF reported before. We found that, although, the dense ceramic specimen of Sm-PMN-PT exhibits exceptionally larged(33), the composite with PT-BNZ exhibited the best piezoelectric and energy harvesting performance. BT, BTS and Sm-PMN-PT composites showed maximum surface power density of 6.24, 12.81 and 23.18 mu W/cm(2), respectively, and volume power density of 416.18, 854.1 and 1104 mu W/cm(3), respectively. Whereas surface power density and volume power density of PT-BNZ was 101.80 mu W/cm(2)and 5088.80 mu W/cm(3)respectively. We have also attempted to establish a correspondence between the piezoelectric response, energy harvesting performance and the poling induced domain reorientation/structural changes in the ceramic grains of the composites.