Cardiac catheterisation, as a day procedure, has been performed at the Royal Perth Hospital since November 1985. During the 23 month period from November 1985 to September 1987, there have been 1398 day procedures carried out. One hundred and twelve patients (8%) required overnight admission as a consequence of the procedure--39 patients for routine observation, 41 patients for minor hemorrhage from the brachial arteriotomy or femoral artery puncture site; 12 patients for severe angina: three patients with reversible ischemic neurological deficits; two patients with stroke; four patients with transient brachial artery occlusion; two patients with arrhythmias and eight patients for miscellaneous reasons. One patient discharged on the day of the procedure required subsequent re-admission for treatment of an acute myocardial infarction. There were no deaths. The financial cost saving to the hospital in real terms is estimated to be $41.50 per patient and to the community a further saving of $25 per patient due to a reduction in sick leave. The minimum total cost saving to the taxpayer for the 1,285 patients managed as day cases was $85,000. Cardiac catheterisation can be performed as a day procedure with low morbidity, low mortality and modest cost savings to a major hospital.