A detailed parametric study has been performed of inert particle dispersion characteristics and their effect on particle temperature in an idealized nonpremixed, reacting co-flow jet. A one-way coupled Lagrangian simulation was used, with the continuous phase solved using the Large Eddy Simulation (LES) technique. The spatial dispersion is characterized by the particle Stokes number and the injection location in both reacting and nonreacting jets. Results are consistent with those previously reported in the literature, where particles with a Stokes number near unity are preferentially-dispersed by the large-scale, coherent vortical structures of the shear layer. The heating characteristics are identified in terms of the governing nondimensional parameters for nonisothermal particulate two-phase flows. It is found that the particle temperature behavior is a strong function of the spatial dispersion behavior. For a majority of initial locations within the jet nozzle, particle heating is hindered by an enhanced spatial dispersion. (C) 2000 Elsevier Science Ltd. All rights reserved.