In 2000 and 2001, The Centers for Medicare & Medicaid Services (CMS) End-Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) project collected data on all in-center hemodialysis (HD) patients in the United States aged ≥12 and <18 years. There were 433 of 486 (89%) patients and 435 of 516 (84%) patients who had the minimum required data submitted and were included in the 2000 and 2001 study years, respectively. There were 188 patients (43%) who had data submitted in both study years, providing longitudinal data on this cohort. A comparison of clinical parameters on these 188 patients in the 2000 and 2001 study years reveals significant improvement in mean calculated spKt/V (1.50±0.36 vs. 1.58±0.30, P<0.01), mean hemoglobin (11.0±1.6 g/dl vs. 11.5±1.3 g/dl, P<0.001), mean ferritin (286±278 ng/ml vs. 460±353 ng/ml, P<0.001 , mean transferrin saturation (27.8±15.1% vs. 31.3± 15.0%, P<0.05), mean serum albumin as measured by the bromocresol green method (3.83±0.54 g/dl vs. 3.95±0.42 g/dl, P<0.01), and mean height standard deviation score (-1.814±1.756 vs. -1.699±1.657, P<0.05). In addition, 20 of 29 (69%) patients who had a spKt/V <1.2 in the 2000 study year had a spKt/V >1.2 in the 2001 study year. Of 68 (44%) patients who had a catheter as their HD access in the 2000 study year, 30 had an arteriovenous fistula or graft in the 2001 study year and 49 of 80 (61%) patients who had a mean hemoglobin <11 g/dl in the 2000 study year had a hemoglobin >11 g/dl in the 2001 study year. In summary, these longitudinal data demonstrate significant improvements in nearly all clinical parameters studied in these adolescent HD patients.