This study aimed to evaluate the diagnostic value of miR-193b-5p and miR-511-5p in sepsis and septic shock from the perspective of immune regulation. Initially, serum exosomal miRNA sequencing was conducted on patients with sepsis (n = 6), septic shock (n = 6), and healthy controls (n = 3). Using bioinformatics analysis, miR-193b-5p and miR-511-5p were identified as immune-related miRNAs differentiating sepsis from septic shock. Subsequently, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to validate the identified miRNAs in a cohort of 90 participants, including 30 patients with sepsis, 30 with septic shock, and 30 general surgery patients serving as controls. The results indicated that miR-193b-5p expression level was significantly reduced in septic patients and septic shock patients compared with healthy controls. Both miR-193b-5p and miR-511-5p exhibited diagnostic potential, distinguishing sepsis from the control group, with area under the curve values of 0.797 and 0.795, respectively (P <
0.05). Furthermore, miR-193b-5p expression level was inversely correlated with C-reactive protein level (r = -0.40, P <
0.001), procalcitonin level (r = -0.31, P = 0.003), and interleukin-6 level (r = -0.39, P <
0.001). A positive correlation was identified between miR-193b-5p and lymphocyte count (r = 0.26, P = 0.014). In conclusion, serum miR-193b-5p demonstrated potential as a diagnostic biomarker for sepsis and was associated with inflammation and immune regulation in sepsis.