Background: Sepsis is the main cause of death in infectious diseases that can be caused by gram-negative or gram-positive bacteria. Definitive therapy for sepsis is antibiotics, depending on blood culture results even though it takes time for bacterial growth. Neutrophil–lymphocyte count ratio (NLCR) is a laboratory parameter that can predict bacterial infection in sepsis patients. NLCR is time-and-cost-effective and easy-to-use in daily practice, in sepsis patients infected with gram-negative, gram-positive, and no bacterial growth based on blood culture results. Materials and methods: This was a comparative study of NLCR and the result of blood culture from sepsis patients. Subjects were obtained from the medical records of patients admitted to our hospital from January 2019 to May 2019. Patients aged over 18 years who were diagnosed with sepsis and had blood culture information were included. Patients with hematological disorder and malignancy were excluded. Sepsis data consisted of gender, age, source of infection, comorbidity, NLCR, and blood culture results. Results: Ninety-four sepsis subjects met the inclusion criteria, and fifty-one subjects (54.25%)—33 subjects (35.10%) with gram-negative bacterial infection and 18 subjects (19.15%) with gram-positive bacterial infection—were included in the analysis due to the completeness of the data. The median NLCR (IQR) was 17.8 (14.3–30.7) in gram-negative, 31.5 (26.3–95.0) in gram-positive, and 22.8 (15.67–22.75) in no bacterial growth (p = 0.001). Conclusion: NLCR can distinguish gram-negative and gram-positive bacterial infections. It also can predict the possibility of pathogenic bacteria that cause sepsis.