Approximately 20-30% of patients on renal replacement therapy (RRT) have cognitive impairment. Less is known about the prevalence of cognitive impairment in patients with advanced kidney disease awaiting the initiation of dialysis. Routine cognitive assessment was implemented in the pre-dialysis clinic, which enabled the Nephrologist and Pre-dialysis Nurse to identify those patients with impaired cognitive function and utilise this information to assess the suitability for self-care treatments, such as peritoneal dialysis, as well as to adapt information to meet their needs. Subsequently, a cross-sectional single-centre audit was undertaken to identify the prevalence of cognitive impairment in 132 consecutive new referrals to the pre-dialysis clinic using the Mini-mental State Examination (MMSE). Twenty percent (95% CI = 0.13, 0.27) were classified as cognitively impaired. Those with cognitive impairment were significantly older, and had lower eGFR and higher serum creatinine. It can be concluded that approximately 1 in 5 patients attending the pre-dialysis clinic has cognitive impairment, which may not be apparent on a routine clinical history. Cognitive function assessment is recommended for all, but particularly to the older patient, before advising on choice of dialysis modality or opting for conservative treatment.