This study examines the indications for performing the Kleihauer-Betke (KB) test and makes recommendations for its use. Results of 523 KB tests performed during 1993 at our hospital (Cleveland, Ohio) are reviewed in conjunction with surgical pathology reports of placental findings, obstetric records, and toxicology results. We conclude that the KB test should be performed following a positive screening test on all Rh negative mothers of Rh positive infants. Additional indications include cases of maternal trauma, unexplained increased maternal alpha-fetoprotein levels, fetal distress with abnormal heart tracings, intrauterine fetal death, and cases of unexplained neonatal anemia. We note that the KB test should not be performed to detect suspected placental abruption.