We developed and introduced into clinical practice a leaflet to improve the delivery of information to patients before obtaining their consent to anaesthesia. The amount of information needs to be what a "reasonable" patient thinks appropriate; therefore we tested patients' responses to three levels of information: "full" disclosure, "standard" disclosure (as contained in our leaflet) and "minimal" disclosure. Forty-five patients scheduled to undergo cardiac surgery were enrolled in the study. None of the information sheets caused a significant change in state anxiety score and only the "full" disclosure significantly increased knowledge about anaesthesia (P = 0.016). All leaflets were easy to understand. When only one leaflet was provided 64-73% of patients thought the content was "just right", whereas when all three leaflets were viewed together, 63% of patients thought the "minimal" leaflet withheld too much information.