This work examines the effect of interface thermal resistance on the estimation of surface temperatures in thin-film/ substrate systems. A radiation-boundary-condition model based on the acoustic mismatch model (AMM) is employed to consider the interface thermal resistance between thin-film and substrate. The inverse beat conduction problem is solved using the space-marching technique. The influences of interface thermal resistance, measurement locations, and measurement errors on this method are studied in detail. Numerical results show that the inverse method accurately estimates surface conditions and temperature distributions in a two-layer system even with an abrupt temperature drop at the interface. Sensor locations and interface thermal resistance only slightly affect the accuracy of the inverse estimation during the transient process when the exact input data (without measurement errors) are applied. However, the inaccuracy might be amplified by the interface thermal resistance and sensor locations if measurement errors exist. (C) 2004 Elsevier Ltd. All rights reserved.