We evaluated the incidence of perioperative hyperkalaemia in end-stage renal disease (ESRD) patients undergoing parathyroidectomy and investigated possible contributors to this phenomenon. This was a retrospective cohort study looking at patients who had undergone parathyroidectomy for chronic kidney disease-associated mineral bone disease (CKD-MBD) at The Alfred Hospital, Melbourne, since 2001. Baseline demographics including age, gender, aetiology of renal failure and mode of renal replacement therapy as well as anaesthetic technique and duration of surgery were studied as possible contributors. Perioperative potassium values were compared to preoperative baseline. Following stratification into normokalaemic and hyperkalaemic groups, demographic and operative data were compared. Twenty-two patients met the inclusion criteria with a median (interquartile range, IQR) age of 48.5 (42-59) years. There was a male predominance of 68%. The median (IQR) surgical time was 131 (115-164) minutes. Potassium levels rose perioperatively, with a 27.3% incidence of perioperative hyperkalaemia. Median duration of surgery was longer in the hyperkalaemic patients (167 minutes versus 125 minutes). Following the withdrawal of cinacalcet, parathyroidectomy is increasingly required in ESRD patients with CKD-MBD. Potentially life-threatening hyperkalaemia poses a significant risk in the perioperative period. Serial electrolyte monitoring is crucial to safety in this patient group. A multidisciplinary approach to perioperative management is required to ensure optimal timing of renal replacement therapy and appropriate means of serial blood sampling.