Introduction. The development of neurodegeneration in Alzheimer’s disease is inextricably linked with oxidative stress, a marker of which is oxidative protein modification. In the tissues of the brain, cerebrospinal fluid and plasma in Alzheimer’s disease, an increase in carbonyl derivatives was recorded. The aim of the study to assess the level of spontaneous and induced oxidative modification of blood plasma proteins, polymorphic nuclear and mononuclear leukocytes in patients with Alzheimer’s disease; determine the number of primary and secondary markers of oxidative stress in the observation and comparison groups; to evaluate the value of the reserve-adaptive potential of plasma and leukocytes in the studied groups. Methods. Spectrophotometric determination of carbonyl derivatives of blood plasma proteins and fractionated leukocytes resulting from spontaneous and metal-catalyzed oxidation. Results. In the blood plasma of patients with Alzheimer’s disease, a significant predominance of secondary markers of oxidative damage to the protein is noted; the total level of products of spontaneous and induced oxidative modification of mononuclear leukocyte protein in patients with Alzheimer’s disease exceeds the similar level in the comparison group; significant depletion of the reserve-adaptation potential of both blood plasma and leukocytes in Alzheimer’s disease was revealed. Conclusion. The development of Alzheimer’s disease is associated with the accumulation of products of oxidative modification of proteins and the depletion of the reserve-adaptive potential of blood plasma and mononuclear white blood cells.