An inverse method is used to experimentally determine the transient heat transfer coefficient distribution over the fin of the second row of a staggered finned tube heat exchanger assembly. The experimental test bench uses an infrared thermography system that records the temperature drop of the circular fin surface during a transient experiment. Based on this unsteady temperature field, a specific inverse method has been developed in order to assess the heat transfer coefficient over the fin. The obtained results show the high accuracy of the inverse process in determining heat transfer coefficient spatial distribution which can be viewed as a ‘‘constant wall temperature heat transfer coefficient” over given interval in the experimental transient method.