Phlegmasia cerulea dolens (PCD) is a rare condition characterized by near-complete to total occlusion of an extremity, leading to discoloration, cyanosis, and pain caused by venous thromboembolism (VTE). The inciting events leading to VTE formation can vary widely and may include factors such as trauma or malignancy. In many cases, the underlying thrombus can be managed with anticoagulation. However, surgical intervention is required in certain situations, such as this patient. Prompt action is essential regardless of the treatment modality, as the underlying disease process can significantly threaten the affected limb. This pathology is associated with a high rate of amputation and mortality. This case report discusses a 69-year-old female with a thrombus affecting the common iliac, external iliac, femoral, popliteal, and tibial veins, resulting in PCD. It emphasizes the importance of urgent intervention and treatment and the severe consequences of this disease process.