Although hemodialysis catheters predispose to infection which, in turn, causes inflammation, we studied whether they induce inflammation independent of infection. We compared the level of the inflammatory marker C-reactive protein (CRP) in maintenance hemodialysis patients, comparing those dialyzed using a non-infected catheter to those using arteriovenous fistulas. All incident patients had catheters and fistula placement at dialysis initiation. In 35 patients the fistulas matured, the catheters were removed and the patients were evaluated at 6 months (catheter-fistula). These results were compared to 15 patients in whom the fistula did not mature and catheter use persisted for 6 months (catheter-catheter). There was a significant 82% reduction in the CRP level in the catheter-fistula group but a 16% increase in the catheter-catheter group at 6 months. The changes in CRP did not differ by gender, diabetes status, or by race, and was not correlated with a change in phosphorus, age, or urea reduction ratio at 1 month following hemodialysis initiation. Decreased CRP was associated with increased hemoglobin and albumin. Patients with persistent fistula use from dialysis initiation through 6 months had consistently low CRP levels over that time period. Our study shows that catheters might contribute to increased inflammation independent of infection, and supports avoidance of catheters and a timely conversion to fistulas with catheter removal.