Infection and sepsis are leading causes of death worldwide but the epidemiology and outcomes are not well understood in resource-limited settings. We conducted a four-year prospective observational study from March 2013 to February 2017 to examine the clinical epidemiology and outcomes of adults admitted with community-acquired infection in a resource-limited tertiary-care hospital in Ubon Ratchathani province, Northeast Thailand. Hospitalized patients with infection and accompanying systemic manifestations of infection within 24 hours of admission were enrolled. Subjects were classified as having sepsis if they had a modified sequential organ failure assessment (SOFA) score ≥2 at enrollment. This study was registered with ClinicalTrials.gov, number NCT02217592. A total of 4,989 patients were analyzed. Of the cohort, 2,659 (53%) were male and the median age was 57 years (range 18–101). Of these, 1,173 (24%) patients presented primarily to the study hospital, 3,524 (71%) were transferred from 25 district hospitals or 8 smaller hospitals in the province, and 292 (6%) were transferred from one of 30 hospitals in other provinces. Three thousand seven hundred and sixteen (74%) patients were classified as having sepsis. Patients with sepsis had an older age distribution and a greater prevalence of comorbidities compared to patients without sepsis. Twenty eight-day mortality was 21% (765/3,716) in sepsis and 4% (54/1,273) in non-sepsis patients (p<0.001). After adjusting for gender, age, and comorbidities, sepsis on admission (adjusted hazard ratio [HR] 3.30; 95% confidence interval [CI] 2.48–4.41, p<0.001), blood culture positive for pathogenic organisms (adjusted HR 2.21; 95% CI 1.89–2.58, p<0.001) and transfer from other hospitals (adjusted HR 2.18; 95% CI 1.69–2.81, p<0.001) were independently associated with mortality. In conclusion, mortality of community-acquired sepsis in Northeast Thailand is considerable and transferred patients with infection are at increased risk of death. To reduce mortality of sepsis in this and other resource-limited setting, facilitating rapid detection of sepsis in all levels of healthcare facilities, establishing guidelines for transfer of sepsis patients, and initiating sepsis care prior to and during transfer may be beneficial.