Introduction: The aim of this study was to reveal the effect of the individual’s lifestyle and personality traits on the disease process in patients with sepsis and to have clinical predictions about these patients. Materials and Methods: The study was planned as a multi-center, prospective, observational study after obtaining the approval of the local ethics committee. Patients were hospitalized in different intensive care units. Besides demographics and personal characteristics of patients, laboratory data, length of hospital and ICU stay, and mortality was recorded. Two hundred and fifty-nine patients were followed up in 11 different intensive care units. Mortality rates, morbidities, blood analyses, and personality traits were evaluated as primary outcomes. Results: Of the 259 patients followed up, mortality rates were significantly higher in men than in women (p= 0.008). No significant difference was found between the patients’ daily activity, tea and coffee consumption, reading habits, smoking habits, blood groups, atopy histories and mortality rates. Examining the personal traits, it was seen that 90 people had A-type personality structure and 51 (56.7%) of them died with higher mortality rate compared to type B (p= 0.038). There was no difference between personalities, in concomitant ARDS occurrence, need for sedation and renal replacement therapies. Conclusion: Among individuals diagnosed with sepsis/septic shock, mortality increased significantly in patients with A-type personality trait compared to other personality traits. These results showed that personal traits may be useful in predicting the severity of disease and mortality in patients with sepsis/septic shock.