We compared the clinical sensitivity and cost-effectiveness of a qualitative assay for choriogonadotropin in human urine ("Icon" hCG) with a quantitative assay of serum from 142 women with pathologically-diagnosed ectopic pregnancy. Results show that although the qualitative assay had a clinical sensitivity for pregnancy of 98.6%, as compared to 100% for the quantitative assay, it was more economical to use, and had a significantly shorter turnaround time. We conclude that qualitative hCG assay of either urine or serum is a good screening method for detecting pregnancy, and can replace the stat quantitative assay in women with suspected ectopic pregnancy. We present a diagnostic algorithm to illustrate the role of qualitative and quantitative hCG assays in conjunction with ultrasonography, culdocentesis, and laparoscopy for diagnosis of ectopic pregnancy.