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Purpose. Improving the efficiency of the model of the radial-axial pump-turbine of the Dniester PSP based on spatial profiling of runner blades using circumferential lean. Methodology. The design of the new runners was carried out by means of spatial profiling of the blades, which differed only in the layout of the profiles (relative position) in the circumferential direction. The blades of the runner models with a diameter of 350 mm were manufactured by 3D printing from PLA plastic. Experimental studies were carried out on the IMEP ECS-30 hydrodynamic test stand, the characteristics of which meet the requirements of the international standard for model acceptance tests of hydraulic machines of various types. Findings. Based on the proposed method of spatial profiling of runner blades, the effect of circumferential lean on the energy performance of pump-turbines is investigated. Characteristics in a wide range of turbine and pump modes of operation of three variants of flow parts are obtained. Parameters of optimal modes and values of maximum efficiency are calculated. A comparison of the energy characteristics in the turbine mode at the constant rotation speed corresponding to the maximum, design and minimum heads of the Dniester PSP is presented. In the pump mode, the dependences of the efficiency curves and heads on flow rate at different values of guide vane openings are shown. Originality. The influence of circumferential lean (spatial profiling) of the runner blades of a radial-axial pump-turbine on the energy characteristics in the turbine and pump modes was established for the first time, which made it possible to significantly increase the level of efficiency in almost the entire range of turbine operating mode. Practical value. The newly designed high-performance runner is planned to be implemented at hydraulic units 5–7 of the Dniester PSP. To confirm the results, it is intended to manufacture and study large-scale models of pump turbines with metal runners together with JSC “Ukrainian Power Machines”. [ABSTRACT FROM AUTHOR]