Although restenosis after percutaneous transluminal coronary angioplasty (PTCA) may have morphologic characteristics which are not similar to the original stenosis, it is unknown if a different morphology is also associated with a different clinical presentation. Eleven consecutive patients with angina and single vessel disease had a recurrence of symptoms and restenosis within 6 months of successful PTCA. Seven patients (group I) complained of spontaneous angina before PTCA and had a positive hyperventilation test, while 4 patients complained of exercise-induced angina and had a negative hyperventilation test (group II). In group I restenosis was associated with the same clinical presentation as before PTCA and the hyperventilation test was positive in 6 patients. The angiographic morphology of restenosis was changed in 4 patients. In group II restenosis occurred with the same clinical presentation as before PTCA, the hyperventilation test was negative in 3 patients while the angiographic morphology of restenosis was unchanged in only 1 patient. Although morphology of restenosis is different from the original stenosis, clinical presentation associated with restenosis is generally the same as before PTCA. The response to vasoactive stimuli is independent from the morphology of the lesion.