The Asbestos Job Exposure Matrix (AsbJEM) has been developed to improve the assessment of occupational asbestos exposure for Australian workers. The objective of the research was to assess the reliability of the AsbJEM and refine it if required. The reliability of the tool was confirmed by the significant association of asbestos exposure with malignant mesothelioma. A minor refinement was made from that study. Dose-response relationships between asbestos exposure and both asbestosis and pleural plaques were also clarified. The AsbJEM provides a reasonable estimate of occupational asbestos exposure and may be effective in estimating the risk of developing asbestos-related diseases.