1. Poultry are usually transported in crates which provide the birds with very limited space. Slaughter transport of male turkeys is often carried out using crates that are 40 cm or less in height where it is not possible for them to stand up. There is little information on how this physical restriction over many hours affects the birds. 2. The aim of the study was to compare the welfare of male turkeys transported in crates 40 cm and 55 cm in height. Observations on the birds' behaviour during lairage, carcass damage and meat quality were carried out after four commercial slaughter transport journeys. 3. Birds in 40 cm crates panted more and lay down more than birds in 55 cm crates during lairage. A large percentage of the carcasses had some damage. Significantly more birds from the 55 cm crates had scratches on their backs than birds from the 40 cm crates. There was no significant difference in meat quality between birds transported in the two crate heights. 4. Both positive and negative effects of increased crate height were established and there is no evidence from this study that merely increasing crate height improves turkey welfare. Other solutions should therefore be sought in order to improve the welfare of birds during transport.