In this paper we studied the effect of aluminum oxide (Al2O3) nanoparticles (NPs) on the accumulation and biomarkers of toxic action of lead (Pb) when co-administered to rats in subacute experiment. 36 Wistar rats with initial body weight 120-140 g were divided into 4 groups. Animal of group 1 (control group) were given distilled water by gavage. Rats in group 2 received Pb acetate solution in a dose of 20 mg/kg body weight (based on Pb), animal in the 3rd and 4th groups additionally to this received suspension of Al2O3 NPs in doses of 1 and 100 mg/kg body weight, respectively. The experiment lasted 22 days. Body and organ weight, standard haematologic parameters, protein, creatinine, uric acid level, aminotransferase activity (ALT and AST) in serum, urinary 5-aminolevulinic acid (5-ALA) concentration were measured. Apoptosis of hepatocytes was studied by flow cytometry. Pb content was determined by atomic absorption spectrometry. It has been shown that the administration of Al2O3 NPs together with Pb resulted in a significant dose-dependent increase in the relative weight of the kidneys (0.88 ± 0.03% and 0.94 ± 0.06% vs. 0.74 ± 0.02% and 0.85 ± 0.01% in control and group 1). The excretion of 5-ALA in the urine of animals treated with lead acetate significantly (p < 0.001) increased compared to the animals of group 1 (0.80 ± 0.08/µmol/l); while any dependence of this parameter on the dose of Al2O3 NPs was absent (p > 0.05) (group 2: 4.54 ± 0.56 µmol/l; group 3: 7.34 ± 1.35 µmol/l; group 4: 5.71 ± 1.74 µmol/l). The hemoglobin content was significantly reduced in animals of groups 2-4 (134.0 ± 2.9; 133.6 ± 1.8 and 129.9 ± 2.9 g/l) compared to the animals of the control group (144.6 ± 1.5 g/l), the dependence of this parameter on the dose of Al2O3 NPs was also absent. A marked and significant increase of the level of glucose has been noticed on the background of the Al2O3 and NPs (7.46 ± 0.49 u 8.24 ± 0.80 vs. 6.28 ± 0.34 mmol/l in group 2), and its level went beyond physiological norms in the 4th group and ANOVA indicated the influence of Al2O3 NPs administration. The toxic effects of lead on hematological parameters of blood on the background of the Al2O3 and NPs weren't weakened, and in the case of hematocrit even enhanced, as evidenced by one-way analysis of variance (p < 0.05). When administered together with the Al2O3 Pd accumulated in increased amounts in the liver [up to 1.96 ± 0.25 (group 3) and 2.16 ± 0.23 (group 4) vs. 1.17 ± 0.19 (group 2) mg/kg] (p < 0.05). Thus, Al2O3 NPs possibly presented as a contaminant in food can enhance the bioavailability of lead and some indices of its toxic action.