['Peritoneal dialysis (PD) is a successful renal replacement therapy; however, long-term PD leads to structural and functional peritoneal damage. Therefore, the monitoring and estimation of peritoneal function are important in PD patients. Oxidative stress has been implicated as one possible mechanism of peritoneal membrane damage. The aim of this study was to evaluate the association between an oxidative stress marker, 8-hydroxydeoxyguanosine (8-OHdG), and peritoneal damage in PD patients.', 'The authors evaluated 8-OHdG in drained dialysate by enzyme immunoassay to investigate the association between 8-OHdG and solute transport rate estimated by peritoneal equilibration test and matrix metalloproteinase-2 (MMP-2) level in 45 samples from 28 PD patients.', 'The 8-OHdG level was significantly correlated with dialysate:plasma creatine ratio (r = 0.463, P < 0.05) and significantly inversely correlated with D/D0 glucose (where D is the glucose level of peritoneal effluents obtained 4 hours after the injection and D0 is the glucose level obtained immediately after the injection) (r = -0.474, P < 0.05). The 8-OHdG level was also significantly correlated with MMP-2 level (r = 0.551, P < 0.05), but it was not correlated with the age of subjects, the duration of PD, or blood pressure.'] Does level of 8-OHdG in drained dialysate appear to be a marker of peritoneal damage in peritoneal dialysis?