Flight can be highly-energy demanding, but its efficiency depends largely on flight style, wing shape and loading, and a range of morphological and lifestyle adaptations that can modify the cost of sustained flight. Such behavioural and morphological adaptations can also influence the physiological costs associated with migration. For instance, during intense flight and catabolism of reserves, lipid damage induced by pro-oxidants increases, and to keep oxidative physiological homeostasis under control, the antioxidant machinery is upregulated. Studies on the oxidative physiology of endurance flight have produced contradictory results, making generalization difficult, especially because multispecies studies are missing. Therefore, to explore the oxidative cost of flight and migration, we explored the association between three measures of the antioxidant capacity (total antioxidant status, uric acid and glutathione concentration) and one measure of oxidative damage of lipids (malondialdehyde) with variables reflecting flight energetics (year-round or specifically during migration) across 113 European bird species using a phylogenetic framework. We found that none of the traits predicting year-round flight energy expenditure, including flight style, wing morphology and flight muscle morphology explained any measures of oxidative state measured during the energy demanding breeding period, suggesting that birds endure their everyday exercise without or low oxidative cost. However, oxidative damage to lipids and one component of the endogenous antioxidant system (uric acid), measured after the end of spring migration on breeding adult birds, increased with migration distance. Our results suggest that migration might have oxidative consequences that are carried over to subsequent life history stages (breeding).