1. Assessment of leukocyte profiles has become an increasingly popular tool in the fields of ecology and ecophysiology. The ratio of heterophils to lymphocytes (H/L ratio) is of special utility, as it reflects physiological adaptation of an organism to cope either with an infection through injury (via heterophils) or a communicable disease (via lymphocytes). Thus, elevated H/L ratios may constitute an adaptation to risky environments (i.e. associated with high risk of injury). While intra-population variation in avian H/L ratio has been extensively studied, we are aware of no studies that linked this trait to life-history components at the inter-specific level. 2. We measured H/L ratio in over 400 shorebirds from 19 species during their autumn migration through Central Europe. Phylogenetically informed comparative methods were used to test whether H/L ratio was related to: i) annual survival and lifespan; ii) migratory effort, as measured with total migration distance and migratory energy reserves; and iii) confounding variables such as body size or breeding latitude. 3. A relatively strong phylogenetic signal and spatial phylogenetic autocorrelation indicated that most diversification in shorebird H/L ratios occurred relatively early in radiation of this group. 4. Comparative analysis gave strong support for the negative associations of H/L ratio with residual lifespan and annual survival. In contrast, we found no support for the effect of migratory behaviour on H/L ratios, suggesting that leukocyte profiles in shorebirds may not constitute an important physiological adaptation for long-distance migration. 5. Our study provided the first comparative evidence for a link between H/L ratios and important life-history traits in birds. Strong negative associations with annual survival and residual lifespan indicate that leukocyte profiles may form an adaptive basis for life-history strategies in birds.