Background: Spontaneous unilateral twin ectopic pregnancy is a rare occurrence worldwide, despite the overall increased incidence of ectopic pregnancy as a result of artificial reproductive technology. There are several factors that have led to the overall increase of ectopic pregnancy in many parts of the developed countries. In this paper, we present a case of spontaneous unilateral twin ectopic pregnancy with documented fetal hearts in a woman with a family history of twins and a single documented episode of Chlamydia trachomatis infection. Introduction: A 23-year-old G3P2, presented with an 8-week history of amenorrhea, lower abdominal pain, watery vaginal discharge, and vaginal spotting. During this hospitalization, her serum β-HCG testing was 21,000 mIU/mL and a transvaginal ultrasonographic examination suggested a nonviable unilateral twin ectopic pregnancy. Two separate fetal hearts were identified. During laparoscopy, a 10 cm mass involving the right fallopian tube was excised. Pathologic evaluat...