In the absence of obvious infection, an abandoned arteriovenous graft (AVG) is generally left in place. This has been thought to be the best solution in view of the surgical procedure that would be required for its removal. However, there are reports of occult infection in these retained AVGs that can lead to significant infectious complications. In addition, there is evidence that abandoned, retained AVGs may contribute to the inflammatory state that exist in association with dialysis patients. This observational report of 100 cases of thrombosed AVG in which the thrombus was cultured at the time of thrombectomy demonstrated a significant degree of bacterial colonization in these cases without evidence of bacteremia. It is proposed that this could be the mechanism by which occult infection in an abandoned, retained AVGs occurs.