The source of hemorrhage in a young woman who required emergency laparotomy for intraabdominal bleeding was found to be a very early primary pregnancy implanted on the undersurface of the right diaphragm, far behind the dome of the liver. Immediately adjacent to this lesion were three tiny foci of endometriosis. This coincidence suggests that the site of nidation may have been a focus of ectopic endometrium rather than peritoneum.