This paper analyzes non-isothermal effects on the efficiency of large-pore catalyst particles, where intraparticle convection may be important. The particle permeability is taken into account by studying the flow field within the particle simultaneously with the mass and the energy transport processes. Two particle geometries, slab and sphere, are considered. Non-isothermal effects are observed on the occurrence of multiple steady states due to reaction ignition. It is found that, when the flow field equations are taken into account, the maximum values of the efficiency and the maximum temperatures reached inside the particle are lower than the ones estimated considering just the mass and energy transport equations.