Abstract Aerospace industry often uses nickel super-alloys for blades of jet engine turbines. The reason is that this material can satisfy numerous extreme requirements, such as e.g. strength even at very high temperatures, resistance to fatigue damage, resistance to fatigue effect of combustion gases, etc. The main requirement is assurance of high operational reliability and safety at exploitation under high temperatures. Long-term service life and material reliability is directly linked to its micro-structure, or with its stability at long-term exploitation. These materials are usually alloyed in a complex manner and they are very complicated from structural viewpoint [1]. Presented article deals with analysis of physical-metallurgical characteristics of cast variants of nickel super-alloys, namely of the types INCONEL 713LC and INCONEL 792 – 5A. Several strengthening mechanisms are applied in these types of super-alloys. Principal mechanism is precipitation strengthening by coherent precipitates of Inter.-metallic phase Ni3Al, or Ni3 (Ti, Al). The analysis as such is based on evaluation of micro-structural parameters of these super-alloys by application of light microscopy, as well as electron microscopy and chemical micro-analysis. Structural analysis with use of light microscopy was performed on the light microscope OLYMPUS IX 71, and electron-microscopic analysis was realised on the scanning electron microscope JEOL JSM – 5510 in the mode of secondary electrons. Local chemical analysis was then made on the electron micro-analyser JCXA 733, equipped with energy-dispersive analyser Sapphire.