Cirrhosis is a serious and irreversible disease. It is end result of hepatocellular injury that leads to both fibrosis and nodular regeneration. Sub-acute bacterial peritonitis is an important complication. Objective: To determine the frequency of spontaneous bacterial peritonitis (SBP) in cirrhotic patients presenting with hypoalbuminemia. Subject and Methods: This was a Cross sectional study that was conducted at Department of Medicine, Shaikh Zayed Hospital, Rahim Yar Khan from 1st Jan 2017 to 31st July 2017 in which 200 cases selected by non-probability, consecutive sampling were selected. The diagnosis of SBP was made according to standard criteria. Results: Out of total 200 patients in present study, there were 114 males and 94 females with mean age of 49.19±6.671 years. There were 110 cases falling in Child Pugh class C and 90 in Class B. SBP was seen in 60 cases (30%). It was seen in 36 males (31.58%) and 24 females (16.44%) out of their respective groups with p value of 0.69. When SBP was compared with respect to age groups, it also did not reveal any significant difference (p= 0.68). However, significant difference was seen when SBP was seen in different child pugh classes; where out of total 60, there were 44 (40%) in Class C and 16 (17.78%) in class B having p value of 0.02. Conclusion: Chronic liver disease is a high burden disease in low socioeconomic countries like Pakistan. Sub-acute bacterial peritonitis is an important complication and child Pugh class C has a significant association with this.