The influence of complete revascularization on long-term outcome of patients with multivessel coronary artery disease undergoing percutaneous transluminal coronary angioplasty (PTCA) was determined by analysis of 10-year survival in 167 consecutive patients treated at Juntendo University Hospital during 1984-1993. Forty-nine patients were completely revascularized and 118 had incomplete revascularization according to the anatomical classification. Among patients with anatomically incomplete revascularization, 56 were categorized as functionally adequate revascularization and 62 as functionally inadequate revascularization according to Faxon's criteria. Baseline characteristics showed incompletely revascularized patients had a higher incidence of prior myocardial infarction triple-vessel disease and/or chronic total occlusion in at least one lesion. The 10-year survival was slightly better in patients with complete (100%) than in those with incomplete revascularization (79%), but not statistically significant (p = 0.089). Event-free survival was not significantly different between the two groups. However, the need for coronary artery bypass surgery was higher in the incomplete revascularization group than that in the complete revascularization group (100% vs 81%, p = 0.013). The influence of the degree of functional revascularization on outcome was not clear in the present study. Long-term survival appeared to be better in patients with complete revascularization than that in patients with incomplete revascularization, but even in the latter, coronary artery bypass grafting in the later period could improve outcome. The effect of functional revascularization status should be further investigated in a larger population.