Alloy 718 retains its mechanical properties at elevated temperatures. Furthermore, its weldability contributes to compatibility with additive manufacturing (AM) techniques such as powder bed fusion-laser beam (PBF-LB). In this study, various heat treatments, including stress relief, hot isostatic pressing (HIP), solution treatment, and aging, were applied to Alloy 718 manufactured by PBF-LB, and the stress-rupture life was investigated, as well as the effect of V-notch on its properties. The heat-treated materials exhibited longer stress-rupture life compared to the as-built material. However, significant anisotropy was observed due to the needle-like δ phase precipitated along the grain boundaries. Furthermore, material subjected to a different heat treatment conditions without δ phase precipitates promoted isotropic behavior. At the same time, notched specimens showed anisotropic stress-rupture life due to the interaction between crystallographic texture and stress state at the V-notch root.