Compounds Pd1, Pd2 and Pd3 are examples of the different structures that can be obtained within the chemical space of the same metal, oxidation state and coordination geometry. All three tetrahedral palladium(II) complexes showed exclusively antifungal activity in the initial CO-ADD screening. The cyclooctadiene compound Pd1 was part of a series of similar platinum complexes that we studied for their antibacterial potency, with some also showing antifungal activity (vide infra). Although Pd1 showed good antifungal activity across all tested strains and no cytotoxicity up to 100 µM, it caused haemolysis at low concentrations, with only a small therapeutic index of 13. Pd2 is a synthon for palladium catalysts. The dinuclear complex can be split into a mono-nuclear compound by addition of suitable ligands. High levels of activity across the fungal panel were observed, with MIC values in the low nanomolar range down to 6 nM against certain strains. At the same time the compound shows some cytotoxicity and significant haemolysis (Table in SI). The high level of activity paired with the only moderate cytotoxicity would still enable a good therapeutic index if derivatives with lower haemolytic properties could be found.