To assess the anti-anginal and anti-ischaemic activity of the beta-blocker atenolol (ATN) and the calcium antagonist nifedipine (NIFE) and their combination in coronary patients, a double-blind, cross-over, placebo-controlled study was performed. Ten male patients (mean age: 58 +/- 2.9 years) suffering from a stable effort angina were studied. The study lasted 14 weeks: after 2 weeks of wash-out, patients were randomly assigned to ATN (100 mg/day) and placebo-NIFE, or placebo-ATN and NIFE (10 mg three times/day), or ATN (100 mg) plus NIFE (10 mg three times/day) for 4 weeks. Maximal symptom-limited stress tests on a bicycle (10 watt/min) during the wash-out period (on days 10 and 14) and at the end of each treatment period were performed. All treatments significantly increased the work load at 1 mm ST depression, the angina threshold and the total work, and reduced ST depression at the maximal common work and at the maximal work. Also the atenolol-nifedipine combination significantly reduced ST depression at maximal common work and maximal work as compared to ATN and NIFE alone. In conclusion, this study confirms the anti-ischaemic and anti-anginal activity of both atenolol and nifedipine in stable effort angina and shows that their combination is able to increase anti-ischaemic activity.