Purpose This study aims to introduce exergy analysis of a three-spool turboprop engine during the complete flight. Design/methodology/approach In this study, a flight scenario of the aircraft is assumed. Operating parameters of the aircraft and its engine are modelled based on the assumed flight scenario with the aid of a genuine code. And then performance analysis of the engine is performed for each flight path point with the aid of exergy. Findings At the end of the study, major exergy parameters of the engine are calculated during the complete flight of a cargo aircraft three-spool turboprop engine. Practical implications Findings of the study may be beneficial for industry and practitioners to improve performance of the evaluated engine. Originality/value To the best of authors' knowledge, this paper presented the exergy analysis of a three-spool turboprop engine during the complete flight for the first time. It was shown how the exergy destruction rate depends on the altitude and manoeuvre.