Five groups of 20 slaughter sheep of approximately 37.9 kg liveweight were transported by road for either three, nine, 15, 18 or 24 hours and three groups were not transported, one of them being deprived of food and water for 24 hours. Before and after transport the liveweight and various blood variables were measured and heart rate and behavioural observations were recorded from subsets of the animals. With increased journey time there was a decrease in liveweight and an increase in the plasma levels of free fatty acids, beta-hydroxybutyrate and urea; however, the changes over 24 hours were similar to those in the group deprived of food and water. In the transported sheep, the heart rate and levels of plasma cortisol and glucose were increased by the stresses of loading and the initial stages of the journey, but after nine hours the sheep appeared, to some extent, to have adapted. They were able to lie down and did not appear to be physically stressed. Measurements of plasma osmolality, total plasma protein and albumin did not indicate that the sheep had become severely dehydrated after 24 hours of transport but upon their return, feeding and drinking activity was greater than that observed before the journey.