BACKGROUND:Atypical haemolytic uraemic syndrome (aHUS) is a progressive, life-threatening, and ultra-rare disease with an estimated prevalence of 5.5 persons per million in England (AGNSS in 2012). OBJECTIVES: There is a lack of literature describing the economic and humanistic burden of aHUS. A patient survey was undertaken to evaluate the impact of aHUS on patients, their carers and society in the UK. METHODS: aHUS patients and their carers were recruited by the UK aHUS Patients and Families Support Group and were asked to complete an online questionnaire. Respondents described the impact of aHUS on daily activities, work and out-of-pocket expenses. RESULTS: CONCLUSIONS: Patient survey results showed that aHUS has a substantial economic burden to patients, their carers and society. The total economic burden from lost productivity of patients, carers and out-of-pocket expenses was estimated to be £9,243 per aHUS patient per year.