Bronchogenic cysts are rare congenital cystic lesions. Their occurrence in the anterior mediastinum as intrathymic bronchogenic cyst is extremely uncommon. These cysts present as mediastinal masses, and are generally asymptomatic and often diagnosed incidentally. Despite being benign, their intrathymic location and variable radiological appearance can mimic more common conditions such as thymomas. Surgical resection is the treatment of choice to confirm the diagnosis. We report a case involving a partial thymectomy performed for a suspected thymoma in the anterior mediastinum, which was subsequently identified on pathological examination as a bronchogenic cyst.