The chapter explores the evolution and future of invasive monitoring in epilepsy surgery, emphasizing the impact of technological advancements and conceptual shifts. The goal of epilepsy neurosurgery is to enhance brain function by precisely targeting and removing malfunctioning brain areas. Due to the brain’s complexity, detailed and accurate information about each patient’s condition is vital. Invasive monitoring, a diagnostic procedure involving the placement of recording electrodes in the brain, provides critical data for crafting tailored surgical strategies. Historically, the use of invasive monitoring evolved with the development of electrocorticography (ECoG) and stereotactic electroencephalography (sEEG). Early implementations relied on ictal symptoms and non-invasive techniques such as EEG, but advancements in electrode placement, notably by Jean Talairach and subsequent pioneers, enabled precise localization of seizure onset zones (SOZ). The regional divide saw North America favoring subdural grids, while Europe preferred sEEG, leading to a revolution in epilepsy surgery practice. Currently, sEEG dominates due to its ability to record deep brain structures and offer comprehensive network analysis. This shift is bolstered by innovations such as robot-assisted stereotaxy and MRI-guided laser therapy. The chapter concludes by highlighting the potential future directions, including enhanced computational analysis, Bayesian approaches, and artificial intelligence, which promise to refine surgical planning and improve patient outcomes.