The present study was undertaken to investigate the protective effect of royal jelly against paracetamol-induced liver damage. The study was conducted in 90 female Swiss Albino mice, and six groups were established. While the first group was maintained as control, Groups 2-6 were administered 200 mg/kg RJ for I (lay, 200 mg/kg RJ for 7 days, 400 mg/kg PAR for I day, 200 mg/kg RJ plus 400 mg/kg PAR for I day and 200 mg/kg RJ for 7 days and then second 400 mg/kg PAR on the 7th day, orally, respectively. It was shown that PAR significantly increased serum ALT, AST, ALP, liver MDA levels and significantly decreased liver GSH-Px activity, when compared to the control group (Group 1). On the other hand, meaningful changes were observed in the biochemical parameters of the group which was administered long-term RJ (Group 6). The aforementioned parameters which were statistically significant were determined to have drawn closer to values of the control group, and among these, the existing statistical differences for MDA level and GSH-Px activity between the trial group (Group 6) and the control group disappeared (Group 1). Compared to the pathological changes observed in the liver parenchyma, remark cords, sinusoids and hepatocytes in the group which was administered paracetamol alone (Group 4), lesions were determined to be less severe particularly in the group (Group 6) which received royal jelly for 7 days prior to paracetamol. In conclusion, the administration of royal jelly as a hepatoprotective agent for 7 days against paracetamol-induced liver damage was determined to exhibit marked protective effect on liver tissue. (C) 2008 Elsevier GmbH. All rights reserved.