SummaryThis case report concerns a 32 year old woman which presented with an upper mediastinal shadow on routine chest X-ray. Fourteen years before she had been examined because of a similar mediastinal mass. In spite of various examinations, among which pneumangiography, a correct diagnosis was not made at that time. Inspection of that very pneumangiogram allowed presently to establish the diagnosis of pseudocoarctation of the aortic arch. The present report thus lively illustrates the misleading character of this vascular anomaly. The clinical importance of its proper recognition is stressed in the discussion.