Atraumatic splenic rupture represents a life-threatening abdominal event that requires immediate diagnosis and prompt surgical treatment to ensure the survival of the patient. Atraumatic rupture is relatively uncommon and can occur either in pathological spleens or, more rarely, in normal ones. It has a high morbidity, frequently with few and non specific signs suggesting its presence, can be associated to other pathologies incidentally discovered by imaging. We present a case, successfully treated, of a 51-year-old man, previously healthy, that referred to our hospital for arterial hypertension and abdominal pain; the patient, for an idiopathic splenic rupture with haemoperitoneum, underwent an open splenectomy whose histology examination showed a normal spleen.