The spleen is the most frequently injured organ following blunt abdominal trauma. However, delayed splenic rupture is rare. As the technical improvement of computed tomography has proceeded, the diagnosis of splenic injury has become easier than before. However, the diagnosis of delayed splenic rupture could be challenging if the trauma is minor and remote. We present a case of delayed splenic rupture in a patient with underlying liver cirrhosis. A 42-year-old male visited our emergency department with pain in the lower left chest following minor blunt trauma. Initial physical exam and abdominal sonography revealed only liver cirrhosis without traumatic injury. On the sixth day after trauma, he complained of abdominal pain and diarrhea after eating snacks. The patient was misdiagnosed as having acute gastroenteritis until he presented with symptoms of shock. Abdominal sonography and computed tomography revealed the splenic rupture. The patient underwent a splenectomy and then underwent a second operation due to postoperative bleeding 20 hours after the first operation. The patient was discharged uneventfully 30 days after trauma. In the present case, the thrombocytopenia and splenomegaly due to liver cirrhosis are suspected of being risk factors for the development of delayed splenic rupture. The physician should keep in mind the possibility of delayed splenic rupture following blunt abdominal or chest trauma.