The four species of Denisonia are small, heavy-bodied, nocturnal elapid snakes. Dis- section of 414 museum specimens provided data on body sizes, reproductive cycles and food habits. All species attain similar body sizes (30-40 cm SVL), and sexual size dimorhpism is negligible. Litter sizes are low (4-7) and offspring measure approximately 12 cm SVL at birth. Two eastern Australian species (devisi and maculata) feed almost entirely on frogs, whereas the western species (fasciata and punctata) feed only on reptiles, especially agamid lizards. These differences probably reflect geographic differences in prey availability, but must also involve differences in foraging strategy: the western Denisonia feed on sleeping diurnal reptiles, whereas the eastern denisonia feed on active nocturnal animals. The east-west dichotomy is consistent with morphological data suggesting that the eastern and western species-pairs within "Denisonia" are only distantly related.