Objective: Comparison the behavior of the scores: MPI, APACHE II, qSOFA, SOFA and SIRS with the mortality prediction at adult patients with abdominal sepsis due to secondary peritonitis. Material and methods: Published articles on the use of the MPI scale and other mortality scales in adult patients with abdominal sepsis due to secondary peritonitis were collected in Medline - PubMed and Cochrane Library databases. A first elimination filter was performed according to the number of duplicate studies found, 43 unique studies were identified, of which they were reviewed according to the inclusion and exclusion criteria, of which only 15 were selected and evaluated in detail. Finally, only 10 articles were included in this systematic review. Study eligibility and quality were then assessed using the STROBE tool. High quality and low risk of bias were evidenced in 7 of the selected studies and 3 studies with low methodological quality and high risk of bias Results: The AUC of the MPI-based studies was 0.72 – 0.979, being lower than the AUC values of APACHE II, 0.86 – 0.982, and higher than the AUC of SOFA, 0.70 – 0.72, showing a consistent superiority of APACHE II on the other scales. Conclusion: APACHE II showed a better positive correlation between observed and predicted mortality rates vs MPI and SOFA in patients with abdominal sepsis due to secondary peritonitis.Objetivo: Comparar el comportamiento de los scores: MPI, APACHE II, qSOFA, SOFA y SIRS con la predicción de mortalidad de pacientes adultos con sepsis abdominal por peritonitis secundaria. Material y Métodos: Se recolecto artículos publicados sobre el uso de la escala MPI y otras escalas de mortalidad en pacientes adultos con sepsis abdominal por peritonitis secundaria en bases de datos de Medline – PubMed y Cochrane Library. Se realizó un primer filtro de eliminación de acuerdo a la cantidad de estudios duplicados encontrados, se identificaron 43 estudios únicos, de los cuales fueros revisados de acuerdo a los criterios de inclusión y exclusión, de los cuales solo 15 fueron seleccionados y evaluados en detalle. Finalmente, solo 10 artículos fueron incluidos en la presente revisión sistemática. Luego se evaluó la elegibilidad y calidad de los estudios utilizando la herramienta STROBE. Se evidenció una calidad alta y un bajo riesgo de sesgo en 7 de los estudios seleccionados y 3 estudios con calidad metodológica baja y alto riesgo de sesgo Resultados: El AUC de los estudios basados en MPI, fue de 0,72 – 0,979, siendo inferior a los valores de AUC de APACHE II, 0.86 – 0,982 y superior al AUC de SOFA, 0,70 – 0.72, mostrando una consistente superioridad de APACHE II sobre las demás escalas. Conclusiones: El APACHE II mostró tener mejor correlación positiva entre las tasas de mortalidad observada y predicha vs MPI y SOFA en pacientes con sepsis abdominal por peritonitis secundaria. Palabras clave: sepsis abdominal, peritonitis secundaria, MPI, APACHE II, qSOFA, SOFA, SIRS. ABSTRACT Objective: Comparison the behavior of the scores: MPI, APACHE II, qSOFA, SOFA and SIRS with the mortality prediction at adult patients with abdominal sepsis due to secondary peritonitis. Material and methods: Published articles on the use of the MPI scale and other mortality scales in adult patients with abdominal sepsis due to secondary peritonitis were collected in Medline - PubMed and Cochrane Library databases. A first elimination filter was performed according to the number of duplicate studies found, 43 unique studies were identified, of which they were reviewed according to the inclusion and exclusion criteria, of which only 15 were selected and evaluated in detail. Finally, only 10 articles were included in this systematic review. Study eligibility and quality were then assessed using the STROBE tool. High quality and low risk of bias were evidenced in 7 of the selected studies and 3 studies with low methodological quality and high risk of bias Results: The AUC of the MPI-based studies was 0.72 – 0.979, being lower than the AUC values of APACHE II, 0.86 – 0.982, and higher than the AUC of SOFA, 0.70 – 0.72, showing a consistent superiority of APACHE II on the other scales. Conclusion: APACHE II showed a better positive correlation between observed and predicted mortality rates vs MPI and SOFA in patients with abdominal sepsis due to secondary peritonitis.