Congenital asplenia (Ivemark syndrome) is usually associated with major cardiac malformations, which determine the clinical presentation and often result in death before 6 months of age. We report the unusual case of a 77 year-old patient with a congenital asplenia that was incidentally detected during a laparotomy for mesenteric vein thrombosis. The other abnormal findings in the abdomen were a para-esophageal hiatal hernia and left kidney hypotrophy. A segmental resection of the mid-jejunum was performed, with uneventful recovery. A thoraco-abdominal CT scan failed to reveal any associated vascular malformations in the retroperitoneum or the thorax. This case suggests that, in some instances, congenital asplenia, when isolated, may remain asymptomatic and be compatible with a long, and functionally normal life.