<p>The research article investigates different heat treatment practices on microstructure and mechanical properties of laser powder bed fusion (LPBF)-processed Inconel 718. The microstructure changes were examined with post-processing short heat treatment cycles (HT700, HT900, HT1100 for 1 hour), standard homogenization plus double aging conditions (DA900, HSA and SA). The defects of as-built samples were reduced due to grain growth, grain boundary migration, recrystallization and phase changes during different thermal cycles. The microstructure investigation was conducted by optical, FESEM-EDS phase, SEM-fractography, XRD, EBSD analysis. Residual stress measurement, tensile test and hardness test were conducted to evaluate mechanical properties on different heat-treated Inconel 718 samples. There was a strength (yield stress) improvement in HT700 of about 63% compared to the as-built sample without a change of phases and strength comparable in HT900 and decreases for HT1100. The homogenization plus double-aged samples alter the γ and laves phase microstructure into δ, γ, γ″ and metal carbides. These microstructure changes impact the mechanical properties. The strength achieved (YS) in DA900, HSA and solution aging (SA) processes were 88.7%, 79.9% and 101%, respectively, as compared to the as-built LPBF-processed Inconel 718. The residual stress was more in DA900 and SA but less in HSA compared to the as-built condition. This investigation anticipated a potential method to improve mechanical properties with the reduction in residual stress (HSA condition).</p> Graphical Abstract <p></p>