The development of two dimensional velocity and temperature profiles are explored for a conducting fluid in the entrance region of straight ducts in the presence of a magnetic field. The partial-differential equations for the momentum and energy are solved by a finite-difference calculational procedure. In laminar flow parallel to the magnetic field, the magnetohydrodynamic (MHD) force is seen to enhance heat transfer slightly due to the suppression of velocity profile development. In laminar flow perpendicular to the magnetic field, higher fields enhance heat transfer by increasing the flow rate near the wall.