Out-patient pre-anaesthesia assessment needs to keep pace with the growing volume and complexity of the ambulatory surgery population. In order to maintain efficiency and patient safety while minimising delays and cancellations, out-patients are routinely screened pre-operatively with several methods. These include questionnaires, telephone interviews, automated interviews, and evaluation at a pre-anaesthesia assessment clinic. Information gained from the pre-anaesthesia screening is then used to order additional laboratory tests and consultations as necessary. Indiscriminate laboratory screening is expensive and of no proven benefit in the out-patient setting. The pre-anaesthesia assessment provides the opportunity to not only evaluate patients' medical conditions but to also discuss the anaesthetic plan, explain risks, and allay anxiety. Addressing these issues in a systematic manner helps to keep complication rates low while maintaining a high degree of efficiency and patient satisfaction.