According to EU legislation sufficient height should be provided to animals during transport. The aim of this study was to investigate effects of different cage heights on turkey welfare. Male turkeys (N=36) weighing between 12.6 and 19.4 kg were confined singly and filmed for six hours in stationary cages (52W x 70L cm) which were either 40, 55 or 90 cm high. A blood-sample was taken after confinement for analyses of creatine kinase (CK), aspartate aminotransferase (ASAT), lactate and heterophil/lymphocyte (H:L) ratio. In addition, four commercial slaughter transports were followed using both 40 (N=504) and 55 cm (N=480) high cages (70W x 115L cm) where birds were kept in groups of four (slaughter weight 12.2±1.2kg (mean±SD)). Observations of behaviour during lairage (standing, lying and panting) and carcase damage (bruises on wings and rump and scratches on the back) were carried out. Birds confined singly in stationary 40 cm cages could not stand up and spent more time lying (Wilcoxon Signed Rank test; P<0.001), turned (P<0.001) and preened (P<0.001) less than birds confined in 55 and 90 cm height. There was no difference in CK, ASAT or H/L ratio between heights but CK increased with increased body weight (P=0.008). Lactate concentrations were significantly lower in 55 cm cage than in the 40 cm cage (Mann-Whitney; P=0.001) but no difference was found between 40 and 90 cm. After commercial transports the turkeys performed more panting (Mann-Whitney; P=0.001), and lying (P<0.001) during lairage in the 40 cm cage. Birds transported in 55 cm cages had more scratches on their backs than birds from 40 cm cages (GLM; F=27.6, P=0.013). While behavioural signs indicated more discomfort in the low cages, scratches during transport could have caused more pain to the birds in the higher cages.