Simple counting equipment and radioiodinated human serum albumin (131IHSA) were used to perform placental localization on 48 pregnant women with antepartum hemorrhage. The level of diagnostic accuracy of 85% compares favorably with more expensive methods. The false-negative diagnosis rate for the whole group was 4% and the false-positive diagnosis rate was 8%. The authors recommend this method of isotope placentography for developing countries because the cost of the equipment, including maintenance, and the isotopes is relatively small, and the radiation hazards are negligible.