Vascular graft infections are rare complications, usually associated with a monomicrobial pyogenic culture. We report a case of vascular graft co-infection with Streptococcus anginosus and Coxiella burnetii, complicated by an aorto-duodenal fistula. Screening for chronic C. burnetii co-infection in at-risk patients might prevent adverse long-term outcomes. (c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).