Symptoms and signs of interstitial pregnancy cannot be differentiated from symptoms and signs of other ectopic pregnancies. Unruptured interstitial gestations are usually diagnosed incidental to the work-up of a suspected ectopic gestation. Unlike some teaching, a characteristic pelvic mass was palpable in 3 of 4 cases. Incomplete induced abortion helped in diagnosing 2 cases. Ultrasound and laparoscopy will aid in establishing the correct diagnosis.