Aim: To assess and compare the validity of 3 mortality prediction systems for the severe sepsis and septic shock patient population. Materials and Methods: The present prospective observational study was conducted in Muzaffarnagar Medical College, Muzaffarnagar among 200 cases. Patients fulfilling all inclusion criteria and exclusion criteria were enlisted in the study after informed consent. Patients were evaluated with Clinical History taking and Physical Examination. Blood sampling for CBC, RFT, LFT and Arterial Blood Gas Analysis was done Patients were evaluated by SAPS II, SOFA and APACHE II at the time of admission. Also, the various scoring models were compared. Patients were given routine medical care and were studied upto discharge or death. Results: The mean SAPS2, APACHE II and SOFA score was higher in the mortality group as compared to the discharge group. The predicted mortality of SAPS 2, APACHE II and SOFA was found to be 56%, 66% and 45% respectively. It was found that SAPS2 and SOFA predicted a slightly lower mortality rate than the actual mortality, whereas APACHE II predicted a higher mortality than the actual mortality. Conclusion: We conclude that the SAPS II score was superior to the APACHE II and SOFA scores for predicting survival in patients with septic shock