The cost effectiveness and clinical utility of a simple, rapid, and accurate pregnancy test in the evaluation of suspected ectopic gestation were studied. The introduction of this qualitative serum assay for human chorionic gonadotropin into our outpatient department during a 1-month period was associated with a significant decrease in culdocenteses (p less than 0.001), ultrasound examinations (p less than 0.025), and hospital admissions (p less than 0.01), with a net projected institutional reduction in health care costs of +123,000 annually.