Primary Klebsiella pneumoniae liver abscess with metastatic complications is a globally emerging infectious disease and is the leading cause of liver abscess in Taiwan. Host immunity and bacterial virulence, especially of the capsular polysaccharide type, are important in determining clinical manifestations. Investigators retrospectively studied the K pneumoniae genotype and capsular serotype from patients with 37 strains of liver abscess; no correlation was noted with genotype, and many genetically different strains caused liver abscess. Although K pneumoniae is prevalent in patients with diabetes, it can attack healthy or alcoholic people as well. Additional studies are needed to explore the mechanisms of bacterial virulence and to optimize treatment strategies. Physicians should be alert to the illness and its complications.