Presented here is the case of a 63-year-old patient with a Streptococcus pneumoniae-infected aneurysm extending from a persistent lobar pneumonia of the left lung into the thoracic aorta. The patient was successfully treated with surgery and high-dose penicillin, and he remained well at 6-month follow-up. A review of the English-language literature over the past 25 years revealed 22 cases of mycotic or infected aortic aneurysms due to Streptococcus pneumoniae; however, none of these cases resulted in a positive outcome for the patient. The characteristics of these cases are discussed.