This is the first case report from Scandinavia of a pyogenic liver abscess caused by a Klebsiella pneumoniae isolate belonging to the international hyper virulent clone ST23. The patient, an 85-year old Caucasian, had no history of foreign travel or any classical predisposing factors for infection. The isolate was hypermucoviscous of capsular serotype K1 and carried the virulence factors aerobactin, allS, kfu and rmpA.