This study analysed the clinical profile, prognosis and consequences on left ventricular function of isolated obstructive atherosclerosis of the right coronary artery in order to establish the indications of percutaneous angioplasty. The inclusion criteria were at least one stenotic lesion greater than 75 p. 100 of a dominant or equilibrated right coronary artery and exclusion of stenosis of the other coronary vessels. A questionnaire was sent to the treating physician and to the patient to establish the actuarial survival (Cutler and Ederer's method). The average period of follow-up was 56 months (range 12 to 70 months). Seventy one patients (average age 53 years) were selected from a series of 2,675 consecutive coronary angiograms performed between 1979 and 1984 (2.7 p. 100). The incidence of previous infarction was 60 p. 100; this was located on the inferior wall in 75 p. 100, inferobasal wall in 12 p. 100 and infero-latero-basal wall in 13 p. 100. Bypass surgery was performed in 7 cases and percutaneous angioplasty in 2 cases. Sixty-two cases were managed medically. Analysis of the 71 angiographic films of the series showed in retrospect an indication for percutaneous angioplasty in 29 patients (42 p. 100 of the series). The 5 year mortality rate was 5.6 p. 100. Death was sudden in the 4 cases observed, including one on the 28th day after bypass surgery complicated by perioperative infarction.(ABSTRACT TRUNCATED AT 250 WORDS)