Spontaneous splenic artery aneurysm (SAA) is a rare but a life-threatening condition. Thus, early diagnoses may increase the chance of survival. A 52-year-old female patient was admitted to the emergency department with a pain that starts from the chest and epigastric region and radiates to back and left arm. The patient prediagnosed as having acute myocardial infarct and was under observation when acute abdomen and hemorrhagic shock developed. After further investigation, the patient was diagnosed as having SAA and has undergone a successful surgery. The patient was fully cured and discharged from the hospital on the seventh postoperative day. The patient originally presented with SAA, although she was primarily observed in the emergency department with acute myocardial infarct diagnosis because of similar symptoms and clinical findings to cardiovascular diseases. When changes in the clinical picture occurred, the patient was reevaluated and had undergone an operation because of SAA rupture. Therefore, physicians should take into consideration of aneurysm rupture in the differential diagnosis of the cardiovascular conditions; otherwise, the patient may lose his/her life.