Escherichia hermannii is an extremely rare etiological agent of invasive infection, and thus, the bacterium was initially considered non-pathogenic. However, in five previously reported case reports E. hermannii has been implicated as the sole pathogen. Our case report describes blood stream infection with E. hermannii in a haemodialysis patient with persisting symptoms, high fever and inflammatory markers despite appropriate antibiotic treatment until replacement of the dialysis catheter. We suspect biofilm formation to be a crucial pathogenic feature for E. hermannii in the maintenance of an infection, which stresses the necessity of antibiotic treatment along with catheter replacement in bloodstream- and catheter-related infection with E. hermannii.