An analytical study is performed to study the effects of chemical reaction and radiation on unsteady hydrodynamic flow past an exponentially accelerated vertical plate with variable temperature and variable mass diffusion. It is assumed that the effect of viscous dissipation is negligible in the energy equation and there is a first order chemical reaction between the diffusing species and the fluid. The flow is assumed to be in x′ -direction which is taken along the infinite vertical plate in the upward direction and y′ -axis is taken normal to the plate. At time t′ > 0, both the temperature and species concentration levels near the plate are raised linearly with time t. The governing equations are solved in closed form by the Laplace transform technique. The velocity, temperature and concentration fields are studied for different physical parameters like thermal Grashof number (Gr), mass Grashof number (Gm), Schmidt number (Sc), Prandtl number (Pr), radiation parameter (R), accelerated parameter (a) and time (t) graphically while the effect of chemical reaction parameter (K) is presented through tables. © 2013 Pushpa Publishing House.