Ten cases of secondary abdominal pregnancy have been studied as a basis for this discussion. While recognizing the possibility of primary abdominal pregnancy, we are of the opinion that its occurrence must be exceedingly rare. The incidence of secondary abdominal pregnancy in our series, reported here, is 0.28 per cent. A relatively long period of sterility preceding the ectopic gestation was a common factor in this series. Pelvic infection, on the other hand, did not seem to play a noticeable part in predisposing the patients to the development of secondary abdominal pregnancy. Although at times a history of disturbed menses was suggestive of ectopic pregnancy, we do not find that it was a guide in diagnosing secondary abdominal pregnancy.Progressive lower abdominal pain, associated with constantly increasing constipation, was an outstanding symptom. The location of the placenta within the abdomen and its tendency to attach itself to the left colon offers an anatomical explanation for both of these symptoms. Abnormal uterine bleeding occurred in six of the 10 cases; while this was a diagnostic aid in pointing to the probability of ectopic gestation, it did not suggest the presence of secondary abdominal pregnancy. Similarly, the laboratory investigation was in no way pathognomonic of this condition.The treatment of secondary abdominal pregnancy is ultimately surgical. Of necessity, surgical judgment alone can determine the time for operation. Preoperative blood transfusion of patients presenting a marked secondary anemia is the one most valuable therapeutic agent in minimizing surgical risk. In addition, postoperative blood transfusions may be employed to great advantage.The surgical management of the attached portions of the placenta will always represent the major problem in any individual case of intraabdominal pregnancy. As reported in this series, we have employed removal of detached fragments of the placenta together with insertion of gauze pack drainage which allows the remaining attached portions to marsupialize. In this series, two deaths followed operation, thus making a 20 per cent mortality. The placenta in one of these patients had produced a complete obstruction of the bowel by its massive implantation in the sigmoid. The patient at the time of operation was practically moribund. The second death might have been prevented had we been able to obtain blood for transfusion prior to operation.