Continuous sutures are generally used to perform anastomoses on vessels less than 2 mm in diameter, but some surgeons advocate interrupted sutures which they claim cause less stenosis and provide better vascular potency in the long term. Arteriovenous fistula for chronic haemodialysis is a good model of anastomosis on 1 to 2 mm wide vessels. We used this model to compare the 2 techniques in 2 randomized groups of 20 patients each. The type of suture (continuous or interrupted) was drawn by lot in non diabetic patients who were having their first fistula for chronic haemodialysis. All anastomoses were performed by end-to-side implantation of a superficial vein onto the radial artery. Prolene 8/0 was used as suture material. The maximum follow-up period was 2 years. No significant difference in vascular potency could be demonstrated between the 3 groups. Thus, continuous sutures performed under suitable conditions can be used to perform with greater ease anastomoses which are as patent as those performed with interrupted sutures.