Without drug treatment, invasive fungal infections are associated with very high mortality. The use of antifungal agents needs to be personalised with regards to infective agent, dose regimen, drug-drug interactions, and tolerability or drug safety issues. Therapeutic drug monitoring (TDM) may help to optimise drug therapy in the individual case, but the clinical indications for TDM differ between different antifungal agents. Here, we aim to summarise the current, clinical view on antifungal TDM in relationship to the clinical pharmacology of each drug.