Wandering spleen is a rare disease resulting from weakness or absence of the ligaments that hold the spleen in its normal position. The hormonal changes and physiologic splenomegaly that occur during pregnancy can induce ligamentous laxity of the spleen. Generally, wandering spleen is easily diagnosed because it is found in an abnormal position upon abdominal computed tomography (CT). However, wandering spleen in the left upper quadrant may be more challenging to diagnose. The treatment for wandering spleen is surgery with the goal of saving the spleen. Presented here is a case of a 34-year-old postpartum female who visited the emergency department of our hospital with severe epigastric pain. Abdominal CT revealed a whirl sign of the spleen located in the left upper quadrant without splenic infarction. She was discharged with the diagnosis of non-specific abdominal pain because her symptoms improved despite her abnormal CT findings. However, she returned to the hospital with abdominal pain after 1 week. Abdominal CT was performed and revealed splenic infarction. If diagnosis is delayed, the spleen cannot be spared due to the development of splenic infarction. Therefore, if the abdominal CT of postpartum women suggests wandering spleen (i.e., whirl sign), a surgical consultation is essential.