An investigation of Dufour effects on unsteady MHD convective flow of micropolar fluid past a vertical moving semi-infinite plate embedded in a porous medium is carried out. The dimensionless governing equations for this investigation are solved analytically using small perturbation approximation. The effect of various dimensionless parameters entering into the problem on the velocity, temperature and concentration profiles across the boundary layer are investigated through graphs. Also, the result of the skin friction coefficient, the rate of heat and mass transfer at the wall are prepared with various values of the parameters. It is observed that the velocity increases with the increase of Dufour number whereas it decreases with the increasing value of Schmidt number, Prandtl number and Eckert number. Also, magnitude of micro rotation increases with the increase of Eckert number.