The use of opioid analgesics in renal dysfunction is potentially problematic and many patients with end stage renal disease are unable to tolerate these medications. A greater understanding of the pharmacokinetics of opioid analgesics is vital in informing safe and effective practice. Using pharmacokinetic analysis, this case study demonstrates for the first time that oxycodone and its metabolites are removed by haemodialysis. As such, care should be taken when using oxycodone in patients undergoing haemodialysis.