Pulse oxymetry, a noninvasive method for determining oxygen saturation (SaO2), is routinly Used in the intensive care units. For determining the changes of SaO2 distal to arterionenous (AV) fistula we perfomed SaO2 measurements by pulse oxymetry in 29 patients with AV fistula. 16 male, 13 female patients ranging between 16- 77 years were included. Measurements were performed from both upper extremity before and at 30. minute of hemodialysis. Paired t test was used to analyse the differences. There was no difference between SaO2 values of both extremities before and during hemodialysis (SaO2=97.3±1.8 vs 97.2+1.5 (p=0.97) and SaO2=96.2±2.5 vs 96.3+2.0 (p=0.96)). SaO2 values decreased significantly in both extremity during hemodialysis (p<0.05). These findings suggested that there is no oxygenation difference caused by AV fistula. The systemic hypoxia during hemodialysis can be diagnosed by pulse oxymetry. This finding suggests to use pulse oxymetry routinly in cases with the risk of hypoxia in hemodialysis.