An inverse radiation analysis is presented for estimating radiative parameters from the temperature measurement in three-dimensional participating media, where radiation and conduction occur simultaneously. The S-N method is employed to solve the radiative transfer equation. The inverse radiation problem is solved through the minimization of a performance function, which is expressed by the sum of square residuals between calculated and observed temperature, utilizing the conjugate gradient method. The present technique is robust and yields accurate estimation of radiative parameters even with noisy measurement of temperature. (C) 2000 Elsevier Science Ltd. All rights reserved.