Background: Oxygen free-radical mediated lipid peroxidation has been implicated in many diseases such as chronic renal failure, hemodialysis and chronic kidney transplant rejection. However, insight into the rule of free radical generation in kidney transplantation has been constrained by the limitations of current indexes of oxidant stress in vivo. Isoprostaglandin F-2 alpha type-III (iPF(2 alpha)-III, formerly known as 8-iso-prostaglandin F-2 alpha) is emerging as a reliable marker of oxidant stress in vivo. The purpose of our study was to investigate iPF(2 alpha)-III formation as an index of lipid peroxidation in the 5 d following kidney transplantation. Methods: Urinary iPF(2 alpha)-III measurements were performed by enzyme immunoassay from day 1 to 5 in 11 patients undergoing kidney transplantation. Results were compared with 11 healthy volunteers matched in sex, age and cigarette smoking. Results: Urinary excretion of iPF(2 alpha)-III at day 1 did not significantly differ between control and transplant group (111 +/- 17 vs. 92 +/- 10 pM/mM creatinine, respectively, NS). Urinary iPF(2 alpha)-III levels did not differ between day 1 to 5, and were not correlated to cold ischaemia time. Conclusion: Our study shows no evidence of enhanced lipid peroxidation in the first 5 d following kidney transplantation.