The differences in behaviour and physiology of calves housed in groups or individually were examined. The observations and measurements were made one hour before and after the morning and afternoon feedings at 2, 4, 6 and 8 weeks of age. The behaviours of interest were feed and water consumption, rumination, licking of objects within the pen, cross-suckling (sucking on body parts of penmates), stereotypies, play behaviour, standing, lying, grooming and restlessness. The physiological variables examined were respiration and heart rate as well as, rectal temperature. The calves were fed colostrum the first three days after birth and were then switched to a milk based diet. At two weeks of age the calves were also provided with calf starter and fodder. The calves that were housed in groups spent more time consuming solid foods, took less time to consume their milk, licked objects throughout the pen more, and cross-suckled more frequently. Individually housed calves spent more time idly standing, sleeping and lying. Rumination did not begin until after 2 weeks of age and was more frequently observed in group-housed calves. The rectal temperature and respiration and heart rates were not affected by housing. By housing calves in groups there welfare can be improved because the calves learn to eat more solid feed at an earlier age, they have access to more free space and are more active, and are provided with the opportunity to interact socially with other calves.