Ectopic pregnancy is currently diagnosed using transvaginal ultrasound and serial serum beta-human chorionic gonadotrophin levels. Diagnosis is often delayed and these tests are time-consuming and costly, both psychologically to the patient and financially to health services. The development of a biomarker that differentiates a tubal ectopic from an intrauterine implantation is therefore important. In the pre-genomic era, a one-by-one scientific approach has revealed over 20 candidate biomarkers that could be used as a test to diagnose ectopic pregnancy although at present their clinical utility is very limited. Recent approaches using microarray and proteomic technology have facilitated the identification of further biomarkers. This presentation will review the state of biomarker discovery for ectopic pregnancy and the challenges for researchers in this area.