Coronavirus disease 2019 (COVID-19) was caused by a novel severe acute respiratory syndrome related coronavirus (SARS-CoV-2) that occurred in late 2019 and soon emerged as a global pandemic. Even after recovering from the initial infection, approximately 45% of patients experience persistent symptoms, known as post-COVID syndromes or long COVID, which can endure for weeks to months. Among the prominent lingering symptoms are fatigue, cognitive impairment (commonly referred to as brain fog), and musculoskeletal disorders. Brain fog manifests as confusion, difficulty focusing, and memory loss. Although the exact cause of cognitive deficits induced by SARS-CoV-2 remains unclear, it is speculated that persistent chronic inflammation resulting from residual virus remnants in the body’s reservoirs and stress-released peptides may play a significant role. This chapter aims to delve into the etiology and recent advancements in treating brain fog associated with COVID-19, shedding light on our understanding of this complex phenomenon and potential therapeutic strategies.