Intraligamentary pregnancy, although rare, tests the physician's acumen in diagnostic and therapeutic skills. Two cases illustrating this entity are presented, the first involves an 18-week fetus, the second a partial hydatidiform mole. Although their presentation and pathogenesis may be indistinguishable, their clinical course and management is different. To the best of our knowledge, this is the first reported case of an intraligamentary pregnancy involving a partial hydatidiform mole.