Background/Objectives: Neutrophils, as the first line of defense in the immune response, produce neutrophil extracellular traps (NETs) upon activation, which are significant in the pathogenesis and organ damage in sepsis. This study aims to explore the clinical value of myeloperoxidase-DNA (MPO-DNA) and cell-free DNA (cf-DNA) in sepsis patients. Methods: Clinical data were collected from 106 sepsis patients, 25 non-sepsis patients, and 51 healthy controls. Sequential Organ Failure Assessment (SOFA) scores were calculated, and levels of MPO-DNA) complexes and cf-DNA were measured using specific kits. Correlation analyses assessed relationships between indicators, while logistic regression identified independent risk factors. Receiver operating characteristic (ROC) curves calculated the area under the curve (AUC) to evaluate the diagnostic value of the biomarkers. Results: Sepsis patients exhibited significantly elevated levels of MPO-DNA and cf-DNA compared to non-sepsis patients and healthy controls. In sepsis patients, MPO-DNA and cf-DNA levels correlated with inflammation, coagulation, and organ damage indicators, as well as procalcitonin (PCT) levels and SOFA scores. Both C-reactive protein (CRP) and cf-DNA were identified as independent risk factors for sepsis, demonstrating moderate diagnostic value. ROC analysis showed that the combination of MPO-DNA and CRP (AUC: 0.837) enhances the AUC value of CRP (0.777). Conclusions: In summary, elevated serum levels of MPO-DNA and cf-DNA in sepsis patients correlate with SOFA scores and PCT levels, providing reference value for sepsis diagnosis in clinical settings.