Adenosine has recently been demonstrated to be a mediator of angina in human beings. The present study was undertaken to document the presence or absence of myocardial ischaemia on clinical, haemodynamic, electrocardiographic and metabolic evidences after intracoronary administration of adenosine. Fifteen patients with chronic stable angina (12 males and 3 females), positive exercise stress test and documented significant stenosis of the left anterior descending coronary artery (LAD) were included in the study. The surface and intracoronary electrocardiograms (ECGs), pulmonary artery diastolic pressure and coronary sinus lactate levels were monitored at baseline and after intracoronary administration of adenosine in all patients. Adenosine was administered intracoronary in doses of 1000-8000 microgram depending on the provocation of chest pain. Typical angina was observed in all patients. There were no signs of ischaemia on surface or intracoronary ECG. There was no statistically significant difference between the pulmonary artery diastolic pressure and coronary sins lactate levels at baseline and post-adenosine administration (p > 0.05). It is concluded that intracoronary administration of adenosine produces chest pain in patients with chronic stable angina by mechanism other than myocardial ischaemia.