Flamelet-based modeling for the evolution of chemically reactive scalars originally designed assuming large Damkohler numbers is extended for situations where local flame extinction and reignition occur. A Lagrangian extension of the flamelet model is formulated, considering a fluid particle that belongs to the same local flame structure as time evolves, where the temporal evolution of the flame structure is determined by, among other things, the scalar dissipation rate associated with the particle. The flamelet model, which is capable of predicting flame extinction but not reignition, is modified by mimicking known reignition scenarios. Model performance is examined using Lagrangian data obtained from direct numerical simulations of non-premixed reactions in isotropic turbulence; the results of the model agree both qualitatively and quantitatively with results obtained from the direct numerical simulations. (C) 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved.