This study analyses literature data to identify optimised print parameters and assesses the consolidation, microstructure, and mechanical properties of Hastelloy-X printed by laser powder bed fusion. Effects of post annealing and hot-isostatic pressing (HIP) on the microstructure and mechanical properties are also revealed. The susceptibility to the solidification cracking was evaluated on the basis the solidification gradient and freezing range obtained via the calculation of thermodynamic phase diagrams (CALPHAD). In addition, the microstructure such as precipitation and chemical segregation were predicted using CALPHAD. The distribution of solidification cracks throughout the builds was quantified for the as-built, annealed and HIP conditions. The assessment reveals the variation of crack density towards the bottom, top and free surface of solid builds. This distribution of cracks is found to be associate with the thermal gradient and effective thermal conductivity, which were estimated by analytical thermal calculations. While the annealing and HIP both can alter the as-printed microstructure thanks to recovery and recrystallisation, the internal micro-cracks and internal pores were only successfully removed by the HIP. In addition to the removal, recrystallisation and precipitation in the HIP (stronger than in annealing), resulting in optimal mechanical properties including a substantial increase in elongation from 13% to 20%, significant improvement of ultimate tensile stress from 965 MPa to 1045 MPa with moderately high yield stress thanks to precipitation.