The anatomic results of reconstructive operation for renovascular disease was analyzed in 161 patients with hypertension who were treated between 1959 and 1983. Arteriosclerotic lesions in 103 patients were repaired by endarterectomy (58 per cent), autologous bypasses (27 per cent) and miscellaneous procedures (15 per cent). Fibrodysplastic lesions in 58 patients were treated by in situ procedures (54 per cent) and by extracorporeal repair and autotransplantation (46 per cent). The results were evaluated by means of angiography at both a short term and long term interval after the operation. Angiograms were taken of 79 per cent of the reconstructions at the short term interval and 65 per cent at the long term interval. For the short term interval, the failure rate of angiographically verified reconstructions was 5.7 per cent for arteriosclerotic and 5.8 per cent for fibrodysplastic lesions. The secondary nephrectomy rate was 3.4 and 4.5 per cent, respectively. Surgical expertise appeared to be an important factor, since all failures but one occurred during the first period of the study. Furthermore, the introduction of extracorporeal reconstruction reduced the failure rate for reconstructive operation for fibrodysplasia; residual lesions in the main renal artery did not occur and those of reconstructed hilar branches were only occasionally observed (6.9 per cent). For the long term interval, failure rates were 17 per cent for arteriosclerotic and 14 per cent for fibrodysplastic lesions. In this respect, the results obtained with endarterectomy and arterial bypasses were superior to those obtained with venous bypasses. We conclude that surgical technique is the most important factor for successful reconstruction and that the use of autologous materials, except autologous veins, is preferred.