Spontaneous perforation of pyometra is a rare pathologic condition that presents as diffuse peritonitis. This report describes an interesting case of spontaneous uterine perforation that mimicked gut perforation clinically and was finally diagnosed at exploratory laparotomy. Although rare, perforation of pyometra should be kept as one of the differential diagnosis in an elderly woman with an acute abdomen. A high index of suspicion is required to make a correct preoperative diagnosis, which allows early intervention, thus reducing morbidity and mortality.