The main objective of this paper is to analyze the effect of MHD, heat generation, radiation and nanoparticle volume concentration on an unsteady natural convective flow of a nanofluid past an impulsively started infinite vertical plate. Nanofluids involving nanoparticles of silver, aluminum oxide, copper and titanium oxide with a nanoparticle volume concentration range smaller than or equal to 0.04 are taken. The numerical solutions of governing boundary value problems are obtained with the help of Laplace transform algorithm and symbolic computation software Maple. The effects of MHD, heat generation, radiation and nanoparticle volume concentration on the velocity and temperature profiles are depicted graphically. The skin friction coefficient and Nusselt number are also investigated.