Liver cirrhosis is characterized by a reduced defensive reaction to bacterial infections and patients with cirrhosis are at increased risk of developing infections, sepsis and death. The most common bacterial infections in these patients are spontaneous bacterial peritonitis, urinary tract infection, pneumonia, skin and soft tissue infection and bacteremia. The most common causes are Gram negative bacteria. The mechanisms of increased susceptibility to infections in cirrhosis are unclear. Numerous mechanisms implicated in altered and diminished immunity include increased shunting of blood away from the liver, qualitative dysfunction of the reticuloendothelial system, decreased opsonisation capacity of the ascitic fluid, and increased intestinal permeability of bacteria and associated endotoxins. Further studies of early diagnosis, prevention and treatment are needed to improve the outcomes in patients with cirrhosis.