Free range exhibits are becoming increasingly popular in zoos as a means to enhance interaction between visitors and animals. However very little research exists on the impacts of visitors on animal behaviour and stress in free range exhibits. We investigated the effects of visitor number on the behaviour and stress physiology of Kangaroo Island (KI) Kangaroos, Macropus fuliginosus fuliginosus, and Red Kangaroos, Macropus rufus, housed in two free range exhibits in Australian zoos. Behavioural observations were conducted on individual kangaroos at each site using instantaneous scan sampling to record activity (e.g., vigilance, foraging, resting) and distance from the visitor pathway. Individually identifiable faecal samples were collected at the end of each study day and analysed for faecal glucocorticoid metabolite (FGM) concentration. When visitor number increased, both KI Kangaroos and Red Kangaroos increased the time spent engaged in visitor-directed vigilance and KI Kangaroos also increased the time spent engaged in locomotion and decreased the time spent resting. There was no effect of visitor number on the distance kangaroos positioned themselves from the visitor pathway or FGM concentration in either species. While there are limitations in interpreting these results in terms of fear of visitors, there was no evidence of adverse effects animal welfare in these study groups based on avoidance behaviour or stress physiology under the range of visitor numbers that we studied.