Objective: Antiphospholipid syndrome (APS) can involve multiple organ systems but endocrine manifestations are rare. In most cases adrenal insufficiency (AI) is the first endocrine manifestation of APS. The prompt diagnosis of AI is critical as this disorder is a life-threatening disease that may lead to fatal outcomes if left untreated. We present a case of AI associated with APS the patient was diagnosed promptly and managed successfully. Methods: The diagnosis of APS was based on a combination of clinical features (deep venous thrombosis and pulmonary embolism) and laboratory findings (lupus anticoagulant, anticardiolipin antibody, anti-beta-2 glycoprotein-I antibody), without alternative diagnosis to explain the clinical findings. AI was diagnosed by low morning serum cortisol with elevated adrenocorticotropic hormone (ACTH) level as well as an ACTH stimulation test. Results: A 50-year-old male presented with deep venous thrombosis of the left extremity diagnosed by compressive ultrasound, and was subsequently diagnosed with a pulmonary embolism by computed tomography angiography and treated with heparin. Two days later, he developed hypotension and bilateral flank pain, and an abdominal computed tomography scan revealed bilateral adrenal hemorrhage. Laboratory results showed a serum cortisol of 3.3 mcg/dL (stress normal, 25 to 35 mcg/dL) and ACTH of 319 pg/mL (stress normal, 128 to 218 pg/mL), consistent with primary AI. Symptoms improved quickly with hydrocortisone therapy. The patient still required glucocorticoid therapy for at least 4 years thereafter. Conclusion: In all cases of adrenal hemorrhage and infarction with unknown etiology, screening with lupus anticoagulant and anticardiolipin antibodies is imperative. Recognition of this high-mortality condition allows for appropriate screening and confirmatory tests leading to a prompt diagnosis and timely management.