Many species have adapted their behaviour to survive in anthropogenically developed environments (hereafter referred to as developed). Eastern grey kangaroos Macropus giganteus are common in developed areas, however very few studies have evaluated their behavioural adaptations to developed landscapes. This study compared the behaviour of eastern grey kangaroos in a developed environment to those surrounded by a natural environment. Data were collected using infra-red camera traps that recorded one minute videos. Population density was calculated using pellet counts. The population of eastern grey kangaroos at the developed site had a higher density, spent more time in larger groups, and had an earlier peak activity time than those at the natural site. More vigilance and less feeding were observed at the developed site. A positive relationship between population density and group size was observed. The higher population density at the developed site is likely to be due to increased resources and restricted dispersal. Kangaroos in developed environments may be active earlier in the day in response to human activity occurring later in the day, and artificial lighting (street lighting) likely impacted nocturnal activity. Increased vigilance may be due to increased human activity, and visual barriers in developed landscapes that reduce the line of sight. Reduced feeding time is probably due to the increased nutritional content of pasture grasses at the developed site. Knowledge of the behavioural differences of kangaroos in developed areas will assist in designing management strategies.