Housing dairy cows offers the possibility to control many aspects of their lives, including accurate rationing, which is especially important for high yielding cows, and rapid health care. In addition, some parasitic diseases are largely controlled by removing cows from pasture. However, housing cows is associated with an increased prevalence of several serious diseases, e. g. mastitis and lameness. In housing systems cows can less readily synchronise their behaviour with other cows, maintain adequate personal space and express oestrus behaviour, compared to cows at pasture. Soft ground and space at pasture facilitate natural locomotion, lying down/standing up motions and resting, without the behavioural abnormalities that may occur inside cubicle houses. Although an inability to perform natural behaviour often impairs health and welfare in housed cows, this is not always the case, and so the precise welfare implications of housing with regards to some of the different types of (natural) behaviour remain tentative. The present findings suggest that dairy cow production based on intensively housed cows is less desirable from the perspective of animal behaviour and health, and hence welfare. However, increasingly larger and more productive dairy herds are utilising intensive housing systems because they facilitate mechanised management systems and a reduction in labour requirements, and the negative implications for welfare are worthy of detailed consideration.