Background: Sepsis is a life-threatening condition caused by a dysregulated host response to infection, leading to tissue and organ damage. Globally, over 19 million people are affected by sepsis each year, with approximately 6 million deaths, making it the third leading cause of mortality (25%). Identifying factors influencing patient outcomes in sepsis and septic shock is therefore of critical importance. Aim: To investigate the factors associated with outcomes in patients admitted to the Intensive Care Unit (ICU) of the Mongolia-Japan Hospital (MJH) with diagnoses of sepsis and septic shock. Materials and Methods: A retrospective study was conducted on patients admitted to the ICU of MJH with sepsis or septic shock during 2023–2024. We analyzed patient data including pre-existing comorbidities, number of infection foci, presence of multiple organ dysfunction, and initial laboratory parameters to determine associations with patient outcomes. Results: Among 430 patients admitted to the ICU during the study period, 136 (31.6%) were diagnosed with sepsis or septic shock. Of these, 94 patients (69.1%) recovered and 42 (30.8%) died. No significant differences were found between survivor and non-survivor groups in terms of comorbidities, white blood cell count, neutrophils, lymphocytes, mature granulocytes, C-reactive protein, or creatinine levels. However, multiple organ dysfunction (p<0.000), infection foci ≥2 (p<0.001), lactate ≥2 mmol/L (p<0.002), and platelet abnormalities (p<0.014) were significantly associated with mortality. The most common sources of infection were intra-abdominal infections (25.7%), pneumonia (25%), skin and soft tissue infections (22.5%), urinary tract infections (16.1%), abscesses (7.35%), tuberculosis (2.2%), and catheter-related bloodstream or neurologically-origin infections (0.73%). Conclusion Intra-abdominal infections and respiratory tract infections were the most common sources of sepsis among ICU patients. Multiple organ dysfunction, having two or more infection foci, elevated lactate levels (≥2 mmol/L), and platelet abnormalities were found to significantly increase the risk of mortality in patients with sepsis and septic shock.