We present a case of splenic abscess causing pneumoperitoneum in a patient with diabetes mellitus. The presentation was initially vague and later evolved to an acute abdomen. An X-ray of the chest did not reveal pneumoperitoneum which was later detected by a CT scan. Exploratory laparotomy was performed under a clinical suspicion of hollow viscus perforation. This case report emphasizes that a ruptured abscess should be included in the differential diagnosis of acute abdomen in an immunocompromised patient.