A chronic ectopic pregnancy is a form of tubal pregnancy in which there is gradual disintegration of the tubal wall with slow and/or repeated episodes of hemorrhaging leading to the formation of a pelvic mass. A review of 22 pathologically proven cases of this entity revealed the pelvic mass to be a hematocele, or a sealed-off inflammatory mass composed of blood clots, organized hematomas, and surrounding adhesions. Sonographically, the abnormality is manifested by an extrauterine, complex mass in the adnexa(e) and cul-de-sac. The mass may obliterate uterine margins and be confused for pelvic inflammatory disease, endometriosis, or uterine leiomyomas. With an increased awareness of this entity and its mildly symptomatic and protracted clinical course, a preoperative diagnosis should be possible.