OBJECTIVES:Renal impairment after transplant is associated to a greater risk of death. It is of interest to asses how and when the diagnosis is made. To evaluate the diagnostic method of renal dysfunction (Clinical or Histological).METHODS:Observational and multicenter study including 872 renal transplant patients with at least  two years post-transplant. Data were retrospectively collected at five time pointssince transplant. Clinicians were asked if they considered that the patient had CGD and also objective criteria (serum creatinine ≥ 2 mg/dl or MDRD ≤ 50 ml/min), were applied. RESULTS:  A total of 872 patients were analyzed 62% male, mean (SD) age 54 (13) years. Ethiology of end stage renal failure: 32.7% chronic glomerulonephritis, 19.8% unknown, 12.4% polycystic disease, 7.6% chronic pielonephritis, 8% diabetes, 5.9% hypertension, 15.7% other. Mean (SD) transplant evolution 8.2 (5.1) years. Mean donor age 42 years. CGD was diagnosed in 35% of the patients according to the investigators’ criteria and in 55.5% according to objective criteria. In 40% of the patients that were diagnosed of CGD by objective criteria the clinician had not considered this diagnosis. Graft biopsy was performed in 31% of patients with investigators’ criteria of  CGD. The presence of proteinuria conducted to a biopsy more than a rise in serum creatinine. Time from transplant to biopsy was greater in patients with antiproteinuric treatment (p=0,032). Immunosuppressive treatment changes were not associated to biopsy histological data. The creatinine slope showed a direct relationship with the total number of treated acute rejections (Pearson’s r: 0,12; p<0.001). CONCLUSIONS: This study shows an existing difference between the clinician’s perception of CGD and  its objective presence. Nephrologists are more sensitive to glomerular disease than to renal impairment itself. Changes in the immunosuppressive treatment due to presence of CGD are performed late and with poor results.