For a total of 349 haemodialysis sessions in 35 patients, 50 special subclavian cannulations were performed. The catheters were implanted infraclavicularly by the Seldinger technique. The average duration of the cannulation period was 26.6 days and the number of dialysis sessions per catheter was 7. Aspects of subclavian cannulation together with indications and complications are described. In three chronically uraemic patients, after 1, 5, and 6 weeks of single-needle haemodialysis, it was noticed that the catheter tip (3-5 cm) inserted into the subclavian vein had broken off. The broken pieces, lodged in the segmental pulmonary arteries, never caused any complication during the observation periods as long as 6, 14 and 33 months. Therefore their removal, either open or transluminal, seemed unnecessary. To prevent complications of similar type it is advisable to avoid single-needle dialysis. Recommended instead is either the double-needle method or the use of a double-lumen catheter.