In this study, we investigated tissue levels of reduced glutathione (GSH) and carnitine as well as thiobarbituric acid reactive substances (TBARS. as a marker of lipid peroxidation) levels in bladder carcinoma and control group of patients. The average GSH, carnitine and TBARS levels for tumor group were respectively 7.11 +/- 3.3 mug/mg protein, 1.81 +/- 0.39 nmol/mg protein, and 4.29 +/- 3.2 mumol/mg protein, versus 14.45 +/- 4.11 mug/mg protein, 2.14 +/- 0.66 nmol/mg protein, and 2.3 +/- 0.6 mumol/mg protein for normal bladder tissues. Thus, tissue reduced glutathione levels (GSH) were significantly lower in patients as compared with the control group (p < 0.001) whereas average TBARS levels in the tumor group were found to be higher than those in control group. The average tissue carnitine levels in the patient group were found to be lower compared with the control group but the difference was not statistically significant (p > 0.05).