Abstract Background Sepsis is considered a major health burden, with high mortality and associated costs. Health indicators are essential to define strategies to improve the treatment of diseases and the epidemiology information of sepsis. Methods This study was a retrospective descriptive study. The purposes to determine distribution and impacts of hospital-acquired sepsis among patients, who were admitted in Rajavithi hospital. The Data was obtained from medical records of 6,673 sepsis from 2015 to 2019 (1st January 2015 - 31st December 2019), using hospital-acquired sepsis and impacts of hospital-acquired sepsis form developed by researcher. Data analysis was performed by using descriptive statistics. Results The major results of this study revealed that 51.1% of sepsis patients were women. The age range of sepsis patient was between 14-100 years old (mean 45.3±6.7 years). There were altogether 6,663 sepsis occurring among these patients. Forty-four point six percent of sepsis was urinary tract infections followed by pneumonia and bloodstream infections (31.2% and 13.7%). The causation of sepsis were related to gram negative bacteria (56.5%), gram positive bacteria (27.2%) and fungus (16.3%). Based on patient department, 57.3% of sepsis occurred in medical department. The length of hospital stay for patients with hospital-acquired sepsis ranged from 6 to 104 days. The average length of stay was 37.6 days. Overall mortality rate of hospital-acquired sepsis was 54.2%. The cost of treatment for hospital-associated sepsis was 9,376.94 USD per case. Sixty-five percent point eight percent of the cost was for antibiotic treatment, 19.6% for equipment, 9.4% for laboratory tests and 5.2% for other procedures. Conclusions Hospital-acquired sepsis among patients can have serious impacts on the patients and increase the economic burden of hospital. Hospital have to determine effective and sustainable hospital-acquired sepsis preventions. Key messages Sepsis is a serious condition that affects the patient. Sepsis are global public health problems. The factors related to mortality are delayed diagnosis, non-intensive care setting admission, delayed antibiotic and multi-organ failure.