Free convection flow of a Jeffrey fluid between two long vertical plates is investigated. The vertical plates are moving with some velocity but in opposite directions. The coupled governing equations, of which one of them is nonlinear, are solved by the linearization technique. It is observed that out of all the physical parameters, the effect of non-Newtonian Jeffrey parameter is the strongest on the velocity and temperature of the fluid. The numerical results obtained reveal many interesting behavior of Grashof number G, Prandtl numbers P, the Eckert number E and the plate velocity V. Furthermore, some deductions are carried out to compare the present results with those previously established. © 2015 Academic Publications, Ltd.