Sixty-one consecutive patients with stable effort angina and single vessel disease underwent successful (reduction of coronary stenoses by greater than or equal to 20%) percutaneous transluminal coronary angioplasty (PTCA). Anatomical results were analysed on the basis of functional evaluation obtained by exercise test (ET) 1 week before (pre-PTCA) and within 1 month after (post-PTCA) PTCA. Total exercise duration and maximal double product significantly increased after PTCA (4.5 +/- 1 min vs 6.9 +/- 1.5 min, p less than 0.001 and 14.1 +/- 3.6 x 1000 mmHg x bpm vs 18 +/- 4.2 x 1000 mmHg x bpm, p less than 0.001). Pre-PTCA ET was positive in 43 patients (70%) and post-PTCA ET in 15 (24%). In patients with post-PTCA positive ET, mean stenosis diameter reduction was significantly lower than that obtained in patients with negative post-PTCA ET (29.6 +/- 8.9% vs 61.1 +/- 18.8%, p less than 0.001). In conclusion, PTCA improved exercise tolerance in the majority of patients with myocardial ischemia, however the definition of anatomical success used in this study appears to be poorly correlated with functional improvement as assessed by ET.