The behaviour of zoo animals differs from their conspecifics in the wild. Understanding behaviour is a key for better husbandry and management. Behaviour defined, and behavioural sampling methods like Ad libitum sampling, Focal sampling, All occurrence sampling, one zero sampling and instantaneous sampling methods for qualitative and quantitative measurement of behaviours were described in this communication. Besides, various methods for development of ethogram, behavioural categories were explained. The role of this behavioural study was to describe the activity pattern, behavioural need, stress, welfare effect of environmental enrichment on stereotypic behaviour, and captive breeding of zoo animals. The significance of behavioural studies in zoo conditions in understanding of species biology, promoting husbandry, breeding and welfare were discussed. Limitations in behavioural research and insurmountable difficulties in zoos discussed. Suggestions were made for collaborative research and scientific management of zoos.