Hyperhomocysteinemia (HHCy) is considered as a risk factor for cardiovascular diseases. The prevalence of HHCy among our renal transplant recipients (RTR) is 65%. Its impact on outcome of renal transplantation is yet unclear. The present study was designed to evaluate prospectively (1) the influence of kidney transplantation on pre-transplant HCy levels (2) the impact of HCy levels on patient and graft outcome, and (3) the relationship of HHCy with post transplant vascular events. We performed a prospective longitudinal evaluation of 82 adult RTR transplanted between July 2001 and Sept 2004. They were randomly selected irrespective of age, sex, type of donor or type of immunosuppression. After consent, clinical and demographic details were collected. Fasting blood samples were collected pre-transplant and every three months post-transplant for 12 months. In addition to total plasma HCy, serum creatinine, eGFR, Hb, albumin, lipids, serum B12 and folate levels were estimated in all subjects, at all sampling times.76 RTR completed the study. HHCy was defined as HCy level ≥15 µmol/L. HHCy was detected in 48.7% RTR, one year post-transplant. The prevalence of anemia (p=0.04) and hypoalbuminemia (p=0.006) were significantly high in RTR with HHCy. Pre-transplant HCy levels decreased from a median of 24.3 to 14.6, one year after transplantation, p<0.0001. HCy levels correlated with serum creatinine (p=0.004), but not with B12 or folate levels. RTR with HHCy had significantly higher episodes of graft infarction (p=0.02) and thrombotic episodes (p=0.02). Five year patient (100% vs. 91.4%; p=0.06) and graft (94.9% vs. 83.3%; p=0.03) survival states were poorer in RTR with HHCy levels. Kidney transplantation lowered HCy concentrations significantly. HHCy is an important independent risk factor for poor patient and graft survival. It is likely that measures to lower HHCy levels will improve kidney transplant outcome. Kidney transplantation, Hyperhomocysteinemia, Outcome