Background: For physicians, the prognostic value of central venous oxygen saturation (ScvO₂) and venoarterial carbon dioxide difference (PvaCO₂) among severe sepsis patients remains unclear. Objective: The aim of this study was for assessment of the prognostic value of PvaCO₂ and ScvO₂ among severe intraabdominal sepsis. Patients and methods: This prospective study included 62 patients with intraabdominal sepsis who were presented at the Emergency Hospital Mansoura University for one year duration. PvaCO₂ and ScvO₂ values were assessed at admission and every 6 hours till the end of 48 hours.  Results: The PvaCO₂ showed significant high levels among the survivor group compared to with the mortality group at 6-48 Hours. Among the included patients, the non survivors tended to have either above or below normal levels of ScvO₂ at 6-48 hours. Multivariate analysis showed that decreased PvaCO₂, increased APACHE-II score, increased SOFA score and increased qSOFA score at admission were shown as independent risk predictors for mortality. Conclusion: Elevated PvaCO₂, above and below normal ScvO₂ levels are associated with poor outcomes and raised risk of mortality. Thus, they hold promise as prognostic values in severe sepsis patients.