Spontaneous bacterial peritonitis (SBP) is an acute bacterial infection of ascitic fluid without an obvious source. The prevalence of SBP in patients with cirrhosis is in the range of 10%–30%. With increasing use of antibiotics, there is a gradual shift in the causative flora of SBP from Gram-negative bacteria to Gram-positive and, more importantly, to drug-resistant bacteria. The aim of this retrospective study on 721 cases was to identify the prevalence of various organisms causing SBP along with their drug sensitivity and resistance patterns. A prevalence of 38.2% culture positivity was observed in our South Indian population. Escherichia coli was the most common pathogen isolated. Third-generation cephalosporins showed high rates of resistance, but a susceptibility of 74.5% to amikacin was found. Nonetheless, 42% of culture-positive isolates exhibited multidrug resistance, the highest rates being seen with Enterococcus faecium (64.2%) and Acinetobacter baumannii (71.4%).