Phlegmasia cerulea dolens (PCD) is a rare and life-threatening complication of extensive deep vein thrombosis (DVT) characterized by severe pain, swelling, and cyanosis of the affected limb. It results from total or near-total occlusion of the deep and superficial veins of a limb, leading to venous congestion and ischemia. It is associated with 40% mortality, more commonly affecting the left lower extremity, with up to 50% of patients requiring limb amputations. PCD complicated by compartment syndrome (CS) with shock and multiorgan failure is very rare. We report the case of a 55-year-old female who presented with sudden onset, severe right lower extremity pain and swelling with associated limb discoloration, paresthesias, and inability to move the toes of her right foot. On examination, there was cyanosis, pulselessness, and tense right leg and thigh compartments. Doppler ultrasonography revealed DVT of the right external iliac extending to the posterior tibial vein. A diagnosis of PCD with CS was made and the patient was immediately started on anticoagulation with unfractionated heparin and emergent decompressive fasciotomies of the right leg and thigh were performed. Following the fasciotomies, she developed circulatory shock and went into cardiac arrest. Despite successful resuscitation, her hemodynamic instability and multiorgan failure precluded further life-saving interventions including thrombolysis or thrombectomy. Limb amputation was declined given her poor prognosis and she passed away shortly thereafter. This case illustrates the rare occurrence of right lower extremity PCD complicated by CS, circulatory shock, and multiorgan failure, which can sometimes occur despite emergency fasciotomy but can be averted with prompt intervention. These complications often preclude immediate thrombolysis and/or thrombectomy. Its recognition, therefore, warrants timely and more aggressive interventions to prevent limb loss or death.