In recent years several mollusc diseases (e.g. Perkinsosis, Bonamiasis, AVG, OOD, ostreid herpes viral disease) have impacted, and continue to impact, Australian fisheries and aquaculture. Similar diseases also affect mollusc aquaculture overseas, e.g. Bonamiasis of oysters in Europe, ostreid herpes virus in Europe and New Zealand. The outcomes of past and present efforts to manage diseases in farmed molluscs have been poor, and few controls have been devised for disease outbreaks in wild populations. Thus these diseases have continued to spread partly due to poor international coordination of response to emerging diseases, lack of sensitive and standardised diagnostic tests, no understanding of whether these diseases arose separately in different countries or whether they have spread internationally, poor understanding of mollusc immunity, poor understanding of pathogen biology in the context of host and environmental change, little information about how the infectious agents are spread within populations, lack of coordinated research on improved measures to avoid disease, inability to predict where and when future threats will arise. These factors suggest a need for an internationally based and coordinated multidisciplinary research approach to ensure the sustainability of mollusc aquaculture and wild mollusc populations. This need was recognised internationally and led to the KBBE Forum workshop on "Disease mitigation and prevention in mollusc aquaculture". One recommendation from the workshop was to hold a future KBBE workshop to address issues concerning mollusc disease diagnostics and would align with several key research areas within the FRDC R&D Plan and be of interest to industry and regulators.