Protein electrophoresis, hematological and cholinesterase values were determined in 32 nestling free-living peregrine falcons (Falco peregrinus) (15- to 27-days-old) in order to establish normal reference values for this population. The following values (mean ± SD) were observed: prealbumin 0.31 ± 0.04 g/dl, albumin 1.25 ± 0.06 g/dl, α₁ and α₂-globulin 0.23 ± 0.02 and 0.16 ± 0.02 g/dl respectively, β-globulin 1.02 ± 0.05 g/dl, γ-globulin 0.060 ± 0.08 g/dl, total protein 3.79 ± 0.18 g/dl, 21.26 ± 1.30 white blood cells/μl (1 × 10³), 2.17 ± 0.07 red blood cells/μl (1 × 10⁶), packed cell volume 37.58 ± 0.82%, hemoglobin 20.96 ± 0.29 g/dl, heterophils 61.14 ± 2.50% and cholinesterase 1,184 ± 75 IU/L. There were no difference in any of these parameters among males and females. The hematological values obtained could be considered as representative values in free-living nestling peregrine falcons.