Natural phytosubstances, such as amygdalin, used in alternative medicine has gained popularity. However, some researchers suspect the protective properties of amygdalin due to a lack of clinical studies. The aim of the present in vivo study was to determine the effect of apricot seed administration on microscopic changes in the liver using a rabbit as a biological model. Sixteen male rabbits 45 days old were randomly divided into four groups (control group without any apricot seed administration, and experimental groups fed by crushed apricot seeds at the doses 60, 300 and 420 mg/kg b.w., mixed with commercial feed), which was administered orally a daily during a ten-month period. The liver tissue samples were evaluated by histological analysis. Significant changes were observed in the microscopic structure of rabbit livers after apricot seed ingestion. The morphometric evaluation of rabbit livers after the application of apricot seeds showed an increase of binucleated cells in the vena centralis region (P≤0.001) at the highest dose and in the peripheral zone at all the doses used (P≤0.001, P≤0.01, P≤0.05) compared to control. On the other hand, distinct inhibition in the number of binucleated cells in the region vena centralis at the doses 300 (P≤0.01) and 420 mg/kg b.w. (P≤0.05) and in the peripheral zone at all the doses used (P≤0.001, P≤0.01) was observed. No significant differences between the control and experimental groups in vena centralis after apricot seed treatment were found (P≥0.05). In addition, the effect of apricot seeds on the relative volume of liver structures – vena centralis, stroma and parenchyma after the application of apricot seeds to rabbit males were assessed. No significant differences between control and experimental groups in the relative volume of vena centralis were found (P≥0.05). On the other hand, the relative volume of the stroma was increased at doses 60 (P≤0.05) and 300 (P≤0.01) mg/kg b.w. Interestingly, the relative volume of parenchyma was significantly decreased (P≤0.05) after the application of apricot seeds in two experimental groups 60 and 300 mg/kg b.w. The current study provides experimental evidence that apricot seeds might affect the liver microscopic structure in rabbits in vivo and thus amygdalin present in apricot seeds might present a potential risk for animal health. However, the toxic effect could not be accurately corroborated, as in many cases changes were dose-dependent and not recorded at the highest dose used in the study.