BACKGROUND Invasive fungal diseases (IFD) are associated with significant treatment-related costs in patients with haematological malignancies (HM). OBJECTIVES The objectives of this study were to characterise the gross and attributable hospitalisation costs of a variety of IFD in patients with HM by linking state-wide hospital administrative and costing datasets. PATIENTS/METHODS We linked the Victorian Admitted Episodes Dataset, Victorian Cancer Registry and the Victorian Cost Data Collection from 1 July 2009 to 30 June 2015. IFD cases and uninfected controls were matched 1:1 based on age within ten years, same underlying HM and length of stay prior to IFD diagnosis. The cost difference between surviving cases and controls, indexed to 2019 Australian dollars (AUD) calculated twelve months from IFD diagnosis, was determined using Poisson and negative binomial regression (NBR). RESULTS From 334 matched pairs, the gross hospitalisation cost of cases was AUD$67 277 compared to AUD$51 158 among uninfected controls, associated with an excess median hospitalisation cost of AUD$16 119 (P