The mahogany glider Petaurus gracilis is an endangered species of gliding possum that is only found within a limited distribution in North Queensland, Australia. The foraging behaviour of the mahogany glider was examined to determine how it changes seasonally, by extensive observations of radio-collared animals over a 2-year period. A total of 440 h was spent following mahogany gliders, of which 222 h of feeding behaviour was observed. Nectar and pollen were clearly the most important food items, comprising between 50 and 99% (mean 72.8%) of the observed feeding time when available. Nectar and pollen were consumed almost exclusively from Myrtaceae species with Eucalyptus, Corymbia and Melaleuca being eaten. Casual observations of a number of faecal samples showed that c. 80% of pollen grains were digested suggesting that pollen is a major source of protein. Other food items consumed included sap from Albizia procera and Acacia mangium, insects, lerps and honeydew, Acacia arils and fruit from mistletoes. In using these food items, the mahogany glider relied on complex seasonal cycles of food availability, requiring a high diversity of plants, with each species having distinct periods when it provides food during the year.