Mounting evidence for increased cardiovascular risk being associated with rosiglitazone had led to Weston Health Trust to begin switching patients to the alternative thiazolidenedione, pioglitazone, at the end of 2007. The opportunity was taken to audit the lipidaemic and glycaemic results of these patients pre- and post-switch. In this predominantly elderly population (median ages: male 66 years; female 72), all markers of lipidaemia and glycaemia significantly improved over 12 weeks. Median changes from baseline to post-switch were: Total cholesterol from 4.0 mmol/L to 3.9 mmol/L; LDL-C from 2.3 mmol/L to 2.1 mmol/L; triglycerides from 1.5 mmol/L to 1.2 mmol/L; HDL-C rose 9% from 1.1 mmol/L to 1.2 mmol/L; non-HDL cholesterol fell 3.0 mmol/L to 2.7 mmol/L and ApoB fell from 0.73g/L to 0.62g/L. Glycaemic parameters also improved, with glycated haemoglobin A1c dropping from 7.2% to 6.2% and fasting plasma glucose reducing from 7.7 mmol/L to 6.4 mmol/L. These results increased the percentage of patients achieving current guideline targets for all measured lipidaemic and glycaemic parameters.