The deformation of diffusion flames by a vortex pair flowfield is examined analytically, in which emphasis is placed on the elfect of heat release due to chemical reaction on the straining of and reactant consumplion by the flames. Two types of initial geometry are considered: one in which a diffusion flame bounding a semi-infinite fuel strip is distorted by the vortex pair, and one in which two infinite diffusion flames bounding an infinite fuel strip interact with the flowfield; these situations are similar to those considered in earlier isodensity modeling (Karagozian and Manda (1986). The chemical reaction is again assunled to be difusion controlled. The procedure for calculating flame deformation. reactant consumption, and the distribution of products about the flame surface accounts for motion of the flame due to the sloichiometry as well as the flowfield. When heat release due to thechemical reaction is represented in terms of local source terms. a significant complication is introduced to the problem, in that the streamlines of the flowfield are not closed. as they are in the isodensity case. The size of the burned core. comprised mostly of combustion products. is much larger when heat release is taken into account, and the effective flame lengths and rates of reactant consumption are reduced, since the flames arc translated radially outward from each vortex struclure. Because the degree of heat release significantly affects the streamline pallern for the vortex pair flowfield, heat release is observed, with stoichiometry, to strongly impact the determination of the "limiting" reactant in reacted core formation.