Background <p>Hughes–Stovin syndrome (HSS) is an exceedingly rare vasculitis characterized by the combination of thrombophlebitis and multiple pulmonary or bronchial artery aneurysms. It predominantly affects young men, is often considered a variant of Behçet's disease, and carries a poor prognosis due to the high risk of fatal hemoptysis from aneurysm rupture. This case report highlights the classic diagnostic and therapeutic challenges of this condition.</p> Case presentation <p>A 20-year-old Arab male smoker presented with a 20-day history of progressive cough, hemoptysis, recurrent oral aphthous ulcers, and significant weight loss. He did not meet the International Study Group criteria for Behçet's disease. Laboratory findings indicated marked systemic inflammation. While a chest radiograph suggested a hilar abnormality, contrast-enhanced computed tomography (CT) pulmonary angiography revealed multiple pulmonary artery aneurysms, the largest measuring 5.2 cm, confirming the diagnosis of HSS. The patient was treated with high-dose intravenous corticosteroids, followed by oral prednisolone, mycophenolate mofetil, and prophylactic apixaban. Despite initial improvement, he experienced a relapse of hemoptysis during steroid tapering. At a 4-week follow-up, his symptoms had resolved, inflammatory markers had normalized, and the largest aneurysm showed a reduction in size. The patient was subsequently scheduled for endovascular coiling.</p> Conclusions <p>HSS is a life-threatening condition that must be considered in young patients with hemoptysis and thrombosis, particularly when clinical features are suggestive but incomplete for Behçet's disease. CT angiography is essential for diagnosis. Treatment centers on aggressive immunosuppression to halt aneurysm progression, requiring a delicate balance with anticoagulation. Endovascular intervention is often necessary for large aneurysms to prevent a fatal outcome.</p>