Erdheim-Chester disease (ECD) is an extremely rare non-Langerhans cell disorder that is believed to include both inflammatory and neoplastic characteristics. It is caused due to genetic mutations in proto-oncogenes like BRAF and MEK, while immunological pathways have an essential role in the onset and progression of the disease. Despite its rarity, ECD poses significant diagnostic and therapeutic challenges due to its heterogeneous clinical presentation and limited understanding of its underlying pathophysiology. Multiple organs can be affected, with the most frequent being long bones, central nervous system and retro-orbital abnormalities, pericardial and myocardial infiltration, interstitial lung disease, retroperitoneal fibrosis, and large blood vessel aberrations. Here, in this review, we comprehensively underline the current knowledge of ECD, including its epidemiology, clinical manifestations, genetics, pathophysiology, diagnostic modalities, and treatment options. By synthesizing existing literature and highlighting areas of ongoing research, this review aims to provide clinicians and researchers with a comprehensive understanding of ECD and guide future directions for improved patient care and outcomes.