An Iterative Regularization Method based inverse algorithm is applied in the present study in simultaneously determining the unknown temperature and concentration-dependent heat and mass production rates for a chemically reacting fluid by using interior measurements of temperature and concentration.It is assumed that no prior information is available on the functional form of the unknown production rates in the present study. Thus, it can be classified as function estimation for the inverse calculations.The accuracy of this inverse heat and mass transfer problem is examined by using the simulated exact and inexact temperature and concentration measurements in the numerical experiments. Results show that the estimation of the temperature and concentration-dependent production rates can be obtained within a very short CPU time on a Pentium IV 1.4 GHz personal computer. (C) 2003 Elsevier Ltd. All rights reserved.