An analytical study is performed to examine the effects of a magnetic field on free convection flow when: (i) plate is moving impulsively with uniform velocityU; (ii) suction velocity normal to the plate is constant; (iii) fluid is subjected to a constant heat source of absorption type; (iv) magnetic lines of forces are assumed to be fixed relative to the porous plate; (v) magnetic field makes an angle α normal to the porous plate. The expressions for the velocity field and skin friction are obtained by the Laplace transform technique. The influences of the various parameters on flow field and skin friction are extensively discussed.