Abstract : Sepsis is one of the main causes of morbidity and mortality in critically ill patients. The innate immune response is the first defense mechanism to prevent infection and fight the pathogen invasion. Cathelicidin is a part of the innate immune system that has antiendotoxin and anti infection functions. In recent study, low levels of cathelicidin are associated with the risk of sepsis and increased mortality. This is a cross-sectional study involved 22 sepsis subjects, 15 septic shock subjects, and 37 non-septic infection subjects. Serum cathelicidin levels were measured by the ELISA method (enzyme-linked immunosorbent assay) with results in ng/mL units of measure. Cathelicidin levels were found to be significantly lower in septic shock than in non septic infections (p=0.030). Cathelicidin levels in septic shock were lower than in sepsis although not statistically significant (p>0.05). Cathelicidin levels in sepsis were lower than in non septic infections but found to be not significant (P>0.05). Analysis of cofounding including age, sex, and comorbidities in this study showed no significant association. Cathelicidin levels are lower in septic shock patients compared to sepsis and non sepsis patients.