Introduction: The prevalence of spontaneous bacterial peritonitis (SBP) in Ecuador is uncertain because studies that allows to observate how this disease is performing and evolving have never been done before. The purpose of this study is to determine the prevalence of SBP episodes in Ecuadorian patients with decompensated liver cirrhosis during a one year period and its association with clinical symptoms, laboratory findings and bacterial pathogens. Methods: A cross-sectional study was conducted in sixty-one Ecuadorian patients who met the inclusion criteria with decompensated liver cirrhosis and ascites during the period between December 2014-December 2015. These patients underwent diagnostic and/or therapeutic paracentesis, whose ascites fluid obtained were analyzed and cultured. Results: A total of 280 paracentesis were performed in 61 patients with a mean of 4.59 paracentesis per patient. Only 63 were classified as SBP, with a mean of one episode of SBP per patient indicating a prevalence of 45%. The majority of patients were male (66%). The most common cause of cirrhosis was NASH (49%). Turbid ascitic liquid was highly seen (SBP: 81%, not SBP: 57%). The most frequent manifestation was abdominal pain (43%) followed by hepatic encephalopathy (41%). With regard to the presentation of SBP, 73% had an increased cell count plus negative cultures and only 27% had positive cultures. The average mortality was 52%, which became higher in patients who had more than one episode of SBP (Odds Ratio: 0.83 and probability of mortality of 45%) Conclusion: It was striking that the most frequent cause of cirrhosis in Ecuadorian patients was due to NASH because in the majority of international statistics the main cause of cirrhosis is hepatitis C virus. Despite being an infectious complication, fever was not a frequent clinical manifestation. Among the characteristics of fluid we can learn that the presence of turbid liquid is not necessarily related to infection, since the proportion of this characteristic was similar in the infected as in the non-infected groups. As E.coli was most commonly identified and there was an important percentage of patients with recurrent SBP episodes, the use of empirical antibiotic therapy against this agent can be an effective prophylaxis strategie. The high prevalence of SBP in our environment and associated mortality requires a study with a larger number of patients to obtain more significant results and have a better understanding in the implications of SBP in Ecuadorian population.Table: Table. Causes of CirrhosisTable: Table. General SummaryFigure: INCLUSION AND EXCLUSION CRITERIAS.