Purpose: The purpose of the paper is to characterize the low cycle fatigue of high - chromium martensitic GX12CrMoVNbN9-1 cast steel from the perspective of the strain and energy criterion. Design/methodology/approach: The tests of fatigue strength within the scope of small amount of cycles to failure at room temperature and elevated temperature (400, 550 and 600°C) were carried out on GX12CrMoVNbN9-1 cast steel. The fatigue tests were run for five assumed levels of controlled amplitude of total strain εac (0.25; 0.30; 0.35; 0.50 and 0.60%). The loading applied in the experiment oscillated sinusoidally with the stress ratio R = -1 and frequency f = 0.2 Hz. The fatigue tests were performed by means of Instron 8501 hydropulser. Tests pieces for the fatigue tests were round and threaded. Findings: The examined cast steel during low cycle fatigue is subject to intense weakening. The period of stabilization was not revealed during the cyclic loading of the cast steel, neither at room temperature, nor elevated one. Moreover, it has been proved that the extent of changes in the cyclic properties is influenced by the level of strain and temperature. Practical implications: Obtained results of the tests are indispensable for the formulation of necessary characteristics of high-temperature creep resisting steels and cast steels. Originality/value: The paper presents the fatigue characteristics of GX12CrMoVNbN9-1 cast steel within the scope of small amount of cycles to failure. The fatigue characteristics of the examined cast steel was developed for both: room temperature and elevated temperature - 400, 550 and 600°C. Fatigue life of the investigated cast steel was described using the equations of Ramberg-Osgood and Manson-Coffin-Basquin, and presented from the perspective of the energy criterion.