The fungal disease mucormycosis has affected Tasmanian platypuses for nearly three decades. We investigated the influences of mucormycosis on the hematologic, plasma biochemical, and other indicators of health in free-living platypuses across 18 Tasmanian river catchments. Live trapping enabled sampling of 161 (apparently) healthy and six ulcerated, mucormycosis-affected platypuses in 75 rivers and streams between January 2008 and June 2009. There were no obvious differences in any hematologic or biochemical measures between healthy and mucormycosis-affected platypuses. However, multivariate analysis revealed that ulceration was associated with living at higher altitudes, low tail fat content (high tail fat index), and low trypanosome load. There was evidence of overall lymphocytosis and monocytosis in animals from areas currently affected by mucormycosis, which suggests that some level of immune response to the introduced fungus is now widespread in disease-affected catchments. Animals from currently, historically, and possibly disease-affected catchments had lower neutrophil counts, mean cell volumes, plasma alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase levels, and higher plasma gamma-glutamyl transpeptidase and platelet counts compared to animals from catchments with no evidence of infection. Reference intervals were generated for all hematologic and biochemical measurements. Since this is the most comprehensive, systematic, and large-scale assessment of the health of the Tasmanian platypus to date, these references intervals should act as the standard against which future studies of platypuses in Tasmania should be compared.