Migration is one of the most critical periods in bird's life. More than 85% of annual mortality occurs during migration period. It is important to understand how birds cope with weather, varying food availability (energy reserves) and predation pressure during migration, and how does corticosterone secretion affect in the process. Corticosterone, the main stress hormone in birds, is important in promoting pre- migratory behaviour by increasing searching behaviour, food intake and diet preferences. Migration modulation hypothesis (MMH) presumes that the baseline levels of corticosterone are elevated in birds preparing for migration to facilitate fuelling, and that the acute adrenocortical stress response to capture and handling is reduced in order to protect skeletal muscles from catabolic activity of high levels of corticosterone. We measured basal and stress- induced levels of corticosterone in barn swallow (Hirundo rustica) plasma samples after 0, 30, and 60 min of capture using corticosterone enzyme immunoassay kit (Assay Designs, USA). We did not find support to the first assumption of MMH. Baseline levels of corticosterone did not increase during autumn. Swallows clearly responded to capture and handling, and the stress response was related to the energetic condition of the bird. Birds in better body condition reduced their adrenocortical stress response as the migration departure approached. This was congruent with the hypothesis. Barn swallows seemed to be able to control the secretion of corticosterone during pre-migratory fuelling.