Recognition of the importance of psychological intervention for surgical patients is a relatively recent development. A range of diverse intervention techniques is now being used to relieve the distress of invasive procedures. We report results of a study in which surgical patients underwent psychological preparation. Intervention was based on a cognitive-behavioral program ("stress inoculation") built on the assumption that it is possible to "immunize" against stress just as it is possible to immunize by inoculation against measles or any other disease. This is done by exposing the individual to the agent (stress) in small doses in order to develop natural resistance. Coping mechanisms then develop so that when a real stressful situation is faced, its demands can be met satisfactorily. The experimental group of 20 patients had a 30-minute conversation with a psychologist in which they were taught various coping devices, including cognitive reappraisal of events surrounding the operation, calming self-talk and cognitive control through selective attention. The 20 in the control group met with the psychologist for the same length of time, but the content of the conversation was completely unrelated to the operation (attention-placebo group). The experimental group needed less post-surgical analgesia than the control group and coped better with the surgical situation in the opinion of the surgeons.