OBJECTIVE The study determined the frequency of common risk factors in patients with ectopic pregnancy in a rural-based population (communities with a population less than 60,000). METHODS The complete medical records were reviewed of all patients with ectopic pregnancy who presented from 1986 through 1992 to the emergency department of a large, rural referral hospital with 65,000 annual visits. RESULTS Among 126 patients with ectopic pregnancy, the predominant risk factors were a history of infertility in 35% and prior tubal operation in 38%. Pelvic inflammatory disease was a risk factor in 17%, a prior ectopic pregnancy in 16%, and a prior appendectomy or pelvic operation in 13%. No risk factor was identified in 47% of the patients. CONCLUSIONS In rural populations, the frequency of common risk factors for ectopic pregnancy is different from that cited in studies of urban populations. Frequently, patients in rural populations have no risk factors whatsoever.