BACKGROUND Access blood flow measurements are considered useful indicators for thrombosis prevention. It was the purpose of this study to compare measurements of access blood flow by two different techniques: duplex doppler and BTM thermodilution. METHODS Patients included must be on chronic hemodialysis on arterioveinous vascular access. They must be in a unit fit with hemodialysis generator equipped with BTM tool. The measurements of access blood flow were made during the first hour of the hemodialysis session. A measurement with each technique was performed for each patient. RESULTS Fifteen patients were included: seven men and eight women, average age 60.8 ± 9.2 years, average weight 76 ± 16 kg, duration on hemodialysis therapy 6.6 ± 6.1 years. Access blood flow was native fistula (14 patients) and a prothetic access (one patient). Average access blood flow was 1088 ± 586 mL/mn (doppler) and 1094 ± 570 mL/mn (BTM). Comparison of access flows obtained by the BTM and doppler techniques showed a strong linear relationship. The average time to perform a measure was six minutes for the doppler technique and five minutes for the BTM technique. No adverse effect was observed in our study. CONCLUSIONS Our study shows a strong correlation between the two techniques (doppler and BTM) for the measurement of hemodialysis access blood flow. The BTM access blood flow measurement technique is fast, economic and made during the hemodialysis session by the nurse.