A dual-porosity, agglomerate-type model for the porous anode and cathode of the molten carbonate fuel cell is developed and used to predict electrode performance in a small, differential-conversion, cell. The model is based on a phenomenological treatment of mass transport, electrode kinetics, and ionic conduction, combined with structural assumptions. The model predicts the steady-state performance, given a minimum number of structural parameters. Comparison with experimental data for a 3 cm/sup 2/ anode and cathode showes good agreement for plausible values of these parameters.