Abstract: The objectives of the present study are investigate the unsteady two-dimensional laminar flow of a viscous dissipative micropolar fluid past a semi-infinite, vertical porous plate moving steadily and subjected to a thermal radiation and mass transfer. The plate moves with constant velocity in the longitudinal direction and free stream velocity follows an exponentially small perturbation law. The Rosseland approximation is used to describe radiative heat transfer in the limit of optically thick fluids. The method of solution can be applied for small perturbation approximation. Numerical results of velocity profiles of micropolar fluids are compared with the corresponding flow problems for a Newtonian fluid. Also, the results of the skin friction coefficient, the couple stress coefficient, the rate of heat and mass transfers at the wall are prepared with various values of the fluid properties and flow conditions.