The appropriateness of coronary angiography and coronary artery bypass surgery in the Trent regional health authority was assessed by comparison with predetermined consensus criteria. 49% of coronary angiographies were considered to be entirely appropriate in relation to the patient's clinical condition, but 21% were deemed inappropriate. Coronary artery bypass surgery was considered appropriate in 55% of patients, but inappropriate in 16%. Audit by "appropriateness" scores may help to determine which patients should first be investigated and treated when resources are limited and waiting lists are long.