Aneurysms involving the main pulmonary artery and its branches are rare. Clinical experience is limited and current knowledge is mainly derived from autopsy findings. This case report describes a patient with a pulmonary artery aneurysm associated with a previous, partially corrected stenotic pulmonary valve. The patient presented with symptoms suggestive of aneurysm dissection three decades after commissurotomy. The diagnostic approach and therapeutic intervention are emphasized with a review of the literature.