Purpose of reviewMalignant mesothelioma is an asbestos-induced, aggressive tumour. In centres acrossthe world, research has focused on evaluating biomarkers for malignant mesotheliomascreening, diagnosis, prognostication and monitoring. With the incidence of malignantmesothelioma expected to increase, it is timely to review the current status of biomarkersin this field.Recent findingsThe majority of recent studies have evaluated the commercial MESOMARK assay in adiagnostic setting. Studies have clarified that soluble-shed mesothelin as well asmesothelin-related peptide are targets of the assay. The assay sensitivity ranges from50% at diagnosis to 84% in advanced disease. The assay has a high level of specificityrelative to benign lung and pleural conditions and is positive in 10–15% of othermalignancies. In a prospective screen of 538 asbestos-exposed workers, 2.8% werepositive; one had lung cancer that was subsequently successfully treated. Thebiomarkers megakaryocyte potentiating factor, osteopontin and CA125, either alone orin combination with soluble mesothelin, have also been assessed.SummaryTo date, soluble mesothelin remains the best available biomarker for malignantmesothelioma. However, a lack of sensitivity for early-stage disease and for all malignantmesothelioma histologies provides motivation for the search of novel malignantmesothelioma biomarkers with greater sensitivity, especially for very early disease.