['We conducted a prospective, uncontrolled, open study to assess the relationship between homocysteine (tHcy) and oxidative stress in chronic, stable, renal transplant recipients (RTR).', 'Included in the study were 17 chronic, stable RTR. All the patients received folic acid (5 mg/day). tHcy and total antioxidant capacity (TAOC) were measured before and at the end of the study period.', 'Mean tHcy concentration was 26+/-10 micromol/L. tHcy significantly decreased during the study period (26+/-10 vs. 18+/-7 micromol/L; P<0.001). There was a significant inverse relationship between TAOC and tHcy (r= -0.33; P=0.01). TAOC significantly increased during the study period (1.49+/-0.23-1.78+/-0.6; P<0.001). There was an inverse relationship between the variation in tHcy and the variation in TAOC (r= -0.44; P=0.01).'] Does treatment of hyperhomocysteinemia with folic acid reduce oxidative stress in renal transplant recipients?