This paper focuses on the exergetic sustainability indicators of turbojet engines. Starting from the sustainability considerations and the second law of the thermodynamics, the paper presents a set of six exergy-based sustainability indicators for the turbojet engine. The indicators of the turbojet engine defined here in conjunction with exergetic analysis and sustainable development are exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental factor and exergetic sustainability factor. These equations are expected to quantify how the small turbojet engines more environmentally benign.