Background: This study evaluated serum vascular endothelial growth factor (VEGF) concentrations in women with normal intrauterine pregnancy (IUP), arrested IUP and ectopic pregnancy (EP). Method: This was a prospective, case-control study evaluating serum VEGF concentrations among 45 early pregnant women who subsequently were found to have an EP, a normal IUP or an arrested IUP (15 women in each group). Patients were stratified according to serum VEGF concentrations above and below 200 pg/ml. Results: There was a significant difference in VEGF concentrations among women with EP, arrested IUP and normal IUP (306.1+/-26.5, 169.7+/-16.6 and 27.0+/-4.4 pg/ml respectively, P<0.001). With a cut-off concentration of 200 pg/ml, serum VEGF could distinguish normal IUP from EP with a sensitivity of 88%, a specificity of 100% and a positive predictive value of 100%. Between EP and arrested IUP, the sensitivity was 87.5%, specificity 75% and positive predictive value of 77.8%. Conclusions: VEGF is a potential marker for EP. Its concentrations in women with EP are higher than in those with normal and arrested IUP.