Expeditions have collected fungi in Antarctic regions since Hooker accompanied the British Antarctic Expedition, 1839-1843, led by Captain Sir James Clark Ross, R.N. Twenty-seven genera of fungi from Macquarie Island are listed in the present account and include plant parasites, saprophytes and soil-inhabiting fungi, both hose with macroscopic fruiting bodies and those which must be isolated from the soil by appropriate laboratory techniques. The numbers of micro-fungi in a range of soils were comparable with figures obtained for more temperate regions. The genus Pencillium was found to be the dominant form. Antibiotic activities were recorded in 36 percent of the soil isolates. The effects of various ecological factors on the fungi of Macquarie Island are considered and the age and stability of the fungal flora are indicated. The distribution of fungi in Antarctic regions is discussed and the need for further exploration indicated.