OBJECTIVES: The study aimed to describe common adverse events associated with atrial fibrillation medications, as well as atrial fibrillation (AF) itself.  The AF and adverse event descriptions were used to estimate societal utility values in the UK.  METHODS: AF base health state descriptions were produced based on EQ-5D survey data with input from patients and clinicians.  Adverse event descriptions were bolted to the EQ-5D derived base AF health states so that the associated disutility of specific treatment adverse events could be described.  The health states described both paroxysmal/persistent and permanent AF along with 14 adverse events.  Interviews with five AF experienced clinicians and six AF patients were carried out to assess the content and face validity of the health states.  In total, 127 members of the UK general public valued the health states in a time trade-off (TTO) interview and ranking task. RESULTS: The study revealed the public preferences for atrial fibrillation and associated adverse event health states.  There was a range of disutility reported for the adverse events from -0.01 for dizziness, -0.03 for rash, -0.08 for diarrhoea, -0.10 for hypothyroidism, to -0.17 for pulmonary complications.  CONCLUSIONS: The study provides insight into the importance of atrial fibrillation treatment adverse events on patient’s quality of life.  As atrial fibrillation is a largely asymptomatic condition, the impacts of treatment adverse events on health related quality of life are amongst the most important factors considered in treatment decisions.  The utility values collected in this study may prove useful in populating cost-effectiveness analyses.