Aspects of the demography of the agile wallaby (Macropus agilis) were investigated in an overabundant population in East Point Reserve, Darwin. The maximum wet-season population size was relatively stable for several years before, and during, this study. Data suggest that the population fluctuated in size seasonally. Life table analysis indicated that mortality of animals up to 18 months old (including pouch young and young-at-foot) was high compared with adult mortality rates. After 18 months of age, mortality rates of males increased throughout life whereas those of females declined slightly and were relatively stable in older age classes. Females reproduced throughout the year, but more large pouch young were observed in the wet season than at other times of the year. The sex ratio of the population was female-biased, probably a result of higher mortality of males in the dry season. Predation by dogs was documented but contributed a relatively small fraction of total annual mortality.