BACKGROUND Renal replacement therapy often requires the insertion of a central venous catheter. The procedure is invasive and can lead to a number of complications. To minimise the risk of such complications, ultrasonography is used. The aim of the present study was to assess the usefulness of ultrasound-assisted vs. traditional method of location of anatomical orientation points for the placement of central venous catheters. METHODS . The prospective and randomised study was carried out, which included 135 patients requiring central venous catheterisation. Patients were allocated into two groups: group I (without ultrasound) - 70 patients and group II (ultrasound guidance) - 65 patients. In the latter, the procedure was performed in 38 cases due to technical problems. The following parameters were compared: age, patient's condition, results of blood clotting tests, and selected renal function parameters. Moreover, the mode of procedure (emergent, scheduled), factors directly affecting the efficacy of catheter insertion and complications (use of anticoagulants, anatomical variants, sites of access, number of cannulation attempts) were analysed. RESULTS. Ultrasound was significantly more commonly used during emergent cannulation procedures (P = 0.002), in the elderly (P = 0.001) and unconscious patients (P = 0.001). Moreover, it was more frequently applied in patients undergoing anticoagulation (P = 0.01) and during the insertion of access through the subclavian and femoral vein (P = 0.013). The percentage of successful first attempt cannulation was higher in ultrasound-guided cases (P = 0.013). There were no significant intergroup differences in the incidence of early complications (P = 0.269). CONCLUSIONS The study findings did not demonstrate significant differences in the incidence of early complications during cannulation with and without ultrasound guidance. The first attempt success rate was found to be significantly higher in cases of ultrasound-assisted central venous catheterisation.