Introduction: The UK Renal Association Clinical Practice Guidelines include clinical performance measures for biochemical variables in dialysis patients [1]. The UK Renal Registry (UKRR) annually audits dialysis centre performance against these measures as part of its role in promoting continuous quality improvement., Methods: Cross sectional performance analyses were undertaken to compare dialysis centre achievement of clinical audit measures for prevalent haemodialysis (HD) and peritoneal dialysis (PD) cohorts in 2009. The biochemical variables studied were phosphate, adjusted calcium, parathyroid hormone, bicarbonate and total cholesterol. In addition longitudinal analyses were performed (2000-2009) to show changes in achievement of clinical performance measures over time., Results: Sixty-one percent of HD and 70% of PD patients had phosphate between 1.1-1.8 mmol/L. Seventy-four percent of HD and 75% of PD patients had adjusted calcium between 2.2-2.5 mmol/L. Twenty-eight percent of HD and 32% of PD patients had parathyroid hormone between 16-32 pmol/L. Seventy-two percent of HD and 83% of PD patients achieved the audit measure for bicarbonate. There was significant inter-centre variation for all variables studied., Conclusions: The UKRR consistently demonstrates significant inter-centre variation in achievement of biochemical clinical audit measures. Understanding the causes of this variation is an important part of improving the care of dialysis patients in the UK., (Copyright © 2011 S. Karger AG, Basel.)