Hydromagnetic free convection laminar flow of an incompressible viscous, conducting fluid through a porous medium past an isothermal porous vertical plate in rotating system with suction/injection at the plate is studied considering jump in temperature. Approximate solutions for primary and secondary velocity of the liquid and temperature field are obtained using single parameter perturbation technique. Expressions for skin-frictions due to primary and secondary velocities and rate of heat transfer are also derived. The results obtained are numerically discussed with the help of tables and graphs.