A Prospective Study of 193 Catheterizations 193 central venous catheters introduced in 142 patients with haematological diseases were studied prospectively for complications in 1984-1992. 165 polyethylene, 14 Hickman and 14 polyurethane catheters were inserted into subclavian vein via infraclavicular access using Seldinger technique exclusively. Except bleeding, that was not serious, immediate complications occurred in 4%. Cumulative duration of catheterizations was 6370 days with median duration of one cannulation of 15 days, range 1 to 489 days. In polyethylene catheters duration of catheterization was influenced significantly by tunnelization. More than half of cannulations were accompanied by technical complications. Incidence of clinical thrombosis was 6.7%. Infectious complications were the most serious with the incidence of proven and suspected catheter-related sepsis of 25.8%, local inflammation of 41.4% and tunnel inflammation of 12.8%. They were caused in 82% of cases by gram-positive bacteria. Catheter-related sepsis was significantly associated with local inflammation, duration of cannulation and leukopenia and application of parenteral nutrition. Hickman catheters had the best "complication to catheterization duration" ratio, that give reasons for using these catheters in this group of patients.