The problem of an oscillatory three dimensional flow past an infinite vertical porous plate with Soret and Dufour effects is presented. Analytical solutions to the coupled non-linear equations governing the flow and heat and mass transfer are solved by regular perturbation technique. The expression for the velocity field, temperature field, species concentration, the Skin-friction, Nusselt number and Sherwood number at the plate are obtained in non-dimensional forms. The velocity distribution, temperature, chemical species concentration, Coefficient of Skin-friction, Nusselt number and Sherwood number at the plate are demonstrated graphically and the effects of different parameters viz. the Suction Reynolds number, the Grashof numbers, the Soret number and the Dufour number on these fields are discussed.
 G. V. Lachmann (Ed.), Boundary Layer and Flow Control, Vol. I and II, Pergamon Press, London, 1961.
 A.Raptis, and N.G.Kafousias, Magneto hydrodynamic free convective flow and mass transfer through a porous medium bounded by an infinite vertical porous plate with constant heat flux, Can. J. Phys .,60, 1725-1729, 1982.
 A.Bejan and K.R. Khair, Heat and mass transfer in a porous medium, Int. J. Heat Transfer ,28, 902-918, 1985.
 N.Ahmed, D.Sarma, and K. Sarma, MHD free and forced convective flow and mass transfer through a porous medium, Far East J.Appl.Math., 21(3), 271-281, 2005.
 R.C.Choudhary and T.Chand, Three dimensional flow and heat transfer through porous medium, Int. J. Appl. Mech. Engineering, 7(4),1141-1156, 2002.
 N.Ahmed and D.Sarma, Three-dimensional Free Convective Flow and Heat Transfer through a Porous Medium, Indian J. Pure and Appl. Math., 28(10), 1345-1353, 1997.
 P.Singh, and J. K. Misra, Three Dimensional Convective Flow and Heat Transfer in a Porous Medium, Indian J. Pure and Appl. Math., 19 (11), 1130-1135, 1988.
 N. C. Jain and P.Gupta, Three Dimensional Free Convection Couette Flow with Transpiration Cooling, Journal of Zhejiang University SCIENCE A, 7(3), 340-346, 2006.
 N.Ahmed., D.Sarma, and D.P.Barua, Three dimensional free convective flow and mass transfer along a porous plate, BAMS, 21, 125-141, 2006.
 M.A. Sattar and M.M.Alam, Thermal-diffusion as well as effects on MHD free convection and mass transfer flow past an accelerated vertical porous plate, Indian J. pure appl. Math., 25(6) ,679-688, 1994.
 N. P Singh, Atul Kumar Singh and Ajay Kumar Singh, MHD free convection MHD mass transfer flow part of flat plate, The Arabian Journal for Science and Engineering, 32 (1A), 93-112,2007.
 M.C.Raju, S.V.K.Varma, P.V.Reddy, and S.Saha, Soret effects due to natural convection between heated inclined plates with magnetic field, Journal of Mechanical Engineering ,39(2), 65-70, 2008.
 N. Ahmed and H.K Sarmah, Effect of thermal diffusion on a three dimensional MHD mixed convection with mass transfer flow past a vertical plate, Journal of energy, heat and mass transfer ,32, 199-221, 2010.
 N.Ahmed and J.K.Goswami, Effect of thermal diffusion on an oscillatory three dimensional flow with mass transfer past an infinite vertical porous plate in presence of heat sink, Int.J.of Appl.Math and Mech., 7(4): 29-52, 2011.
 R.G.Mortimer and H.Eyring, Elementary transition state theory of the Soret and Dufour effects, Proc. Natl. Acad. Sci. USA, 77(4), 1728-1731, 1980.
 M. S.Alam, M. M. Rahman, and M. A. Samad, Dufour and Soret effects on unsteady free convection and mass transfer flow past a vertical porous plate in a porous medium, Nonlinear Analysis: Modelling and control, 11 (3), 217-226, 2006.
 M. S.Alam, and M. M.Rahman, Dufour and Soret effects on mixed convection flow past a vertical porous flat plate with variable suction, Nonlinear Analysis: Modelling and control,11(1), 3-12, 2006.
 M.Ferdows, M.Ota, M.S.Alam and M.A.Maleque, Dufour and Soret effects on steady free convection and mass transfer flow past a semi-infinite vertical plate in a porous medium, Int. J. of Applied Mechanics and Engineering, 11(3), 535-545, 2006.
 S.S. Motsa, On the onset of convection in a porous layer in the presence of Dufour and Soret effects, SJPAM, 3, 58-65, 2008.
 P.S.Reddy and D.R.V.P.Rao, Combined influence of Soret and Dufour effects on convective heat and mass transfer flow through a porous medium in cylindrical annulus with heat sources, African Journal of Mathematics and Computer Science Research, 3 (10),237-254, 2010.
 M.N.R.Shekar and J.V.Madhu, Effects of Dufour and Soret on steady MHD mixed convection flow past a vertical porous flat plate with variable suction, International J.of Multidispl, Research & Advcs. in Eng. (IJMRAE), 3(II), 35-44, 2011.
 G.Lorenzini, L.A.O.Rocha, C.Biserni, E.D.Dos Santos and L.A.Isoldi,Constructal design of cavities inserted into a cylindrical solid body, ASME Journal of Heat Transfer, 134( 7), 071301 1 -1 6, 2012.
 G.Lorenzini, C.Biserni, F.L.Garcia,and L.A.O.Rocha, Geometric optimization of a convective T-shaped cavity on the basis of constructal theory, International Journal of Heat and Mass Transfer, 55(23-24), 6951-6958, 2012.