Asbestos-associated malignancies are one of the major industrial hazards of recent decades and will continue to be so until beyond the end of the century. It has been estimated that, in the United States alone, there will be 131,200 cancer deaths as a result of asbestos exposure. At present the early lesions are detected radiologically, by which time intervention is no longer effective. The aim of this study was to test the value of a battery of serum biomarkers in the early detection of malignancy and in distinguishing between the early stages of mesothelioma and bronchogenic carcinoma. Many of the biomarkers had no discriminating value but on the basis of four such markers (namely TPA, CEA, HA and ferritin) it has been possible to distinguish between the late stages of the two malignancies and asbestosis. The results are discussed in terms of their possible application to the detection of early pre-malignant lesions in a screened population of asbestos-exposed persons, with the aim of attempting to prevent cancer death in such early detected cases.