In this study, a conjugate gradient method based inverse algorithm is applied to estimate the inlet jet temperature in an impinging jet cooling problem. Given the maximum allowable plate temperature and the extent of the area on plate where temperature needs to be controlled, the jet temperature required to meet the two demands can be determined. The tests in two scenarios show that very accurate inlet jet temperatures were returned, resulting in a maximum temperature less than 1% difference with the specified temperature within the specified area. The technique presented here can be a great assist to engineers to design adequate thermal management systems for devices or processes requiring jet impingement cooling. (C) 2010 Published by Elsevier Ltd.