An enzyme-linked immunosorbent assay (ELISA) for the detection of antitetanus antibodies was developed using aluminum-absorbed tetanus toxoid as the coating antigen. The assay was tested by measuring antitetanus antibody levels in serum obtained from subjects before and after immunization with the aluminum-absorbed tetanus suspension. The specificity of the antibodies for tetanus antigen was tested both before and after antitetanus activity was removed with tetanus antigen-coated beads. Also, the activities of the sera were compared with those of a commercially available test. Our results indicated that the aluminum-absorbed tetanus suspension can be coated onto standard polystyrene ELISA plates and used to measure antibody titers to tetanus toxoid.