A meta-analysis of five cohort studies of 580 patients with cirrhosis showed that Gram-negative bacteria were more likely to cause abdominal infections than Gram-positive bacteria (risk difference 0.15; 95% CI 0.09–0.20). Mortality in gram-negative infections was 10% higher (hazard difference 0.10; 95% CI 0.01–0.20). Gram-negative bacteria had an almost threefold higher risk of multidrug resistance (MDR) compared to Gram-positive bacteria (hazard ratio 2.94; 95% CI 1.87–4.64). An increased proportion of gram-positive infections has been observed with fluoroquinolone prophylaxis and invasive procedures. The predominance of gram-negative bacteria was more pronounced in spontaneous bacterial peritonitis (SBP) than in other abdominal infections. Patients in the intensive care unit had a higher proportion of gram-positive organisms and a higher risk of gram-negative MDR, while differences in mortality between groups were smaller, which is related to the pathophysiology of acute liver failure and sepsis. No significant publication bias was detected, which supports the reliability of the results.