We present the dual reciprocity boundary element method (DRBEM) solution to magnetohydrodynamic (MHD) flow in a single and two parallel ducts which are separated by conducting walls of arbitrary thickness in the direction of external magnetic field. The DRBEM discretized coupled MHD convection-diffusion equations in the ducts and the Laplace equations on the shared walls are solved as a whole by using constant boundary elements with the coupled induced current wall conditions. It is shown that, the conducting walls in the double ducts have a strong influence on the currents near the walls, and the core flow increases on the co-flow case but there is a strong reduction in the core flow in the counter-flow case. The coupling between the ducts with conducting thick walls induces reversed flow and counter current flows which may be used for the heat and mass transfer in fusion applications. The proposed numerical scheme using DRBEM captures the well-known MHD flow characteristics when Hartmann number increases.