Combined effects of hydrodynamic slip, magnetic field, suction/injection and convective boundary conditions on the global entropy generation in steady flow of an incompressible electrically conducting fluid through a channel with permeable plates are studied. Analytical solutions of the governing equations are obtained in closed form. Particularly, using thermal boundary conditions of the third kind, the temperature field is derived analytically. Also, the influences of the governing parameters on global entropy generation are discussed in detail and depicted graphically. The analysis of our results indicates that entropy generation minimization can be achieved by appropriate combination of the geometrical and physical parameters of the system. It is possible to determine optimum values of Hartmann number, Biot number and Prandtl numbers which lead to a minimum global entropy generation rate. The effects of slip flow on the optimum values of some other parameters are also explored. (C) 2014 Elsevier Ltd. All rights reserved.