Foramen of Morgagni hernias are rare diaphragmatic hernias, usually occurring on the right and located in the anterior mediastinum. Adult patients diagnosed with a foramen of Morgagni hernia are usually asymptomatic and associated with obesity, trauma or other causes of increased intraabdominal pressure. Plain pulmonary roentgenogram, radiological studies of the gastrointestinal system with contrast material, computerized tomography and magnetic resonance imaging studies are helpful in diagnosis. In this article, a 78-year-old female case with a Morgagni hernia incidentally diagnosed on chest X-ray is presented.