Background: Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Several biomarkers have been suggested to aid in the management of sepsis. Multiple micro-RNAs, a class of regulatory ribonucleic acids, have been studied in sepsis patient for a potential role in diagnosis and prognostic assessment. Aim of the Work: To study the diagnostic and prognostic values of serum expression of miRNA-223, miRNA-193* and miRNA-150 in adult sepsis patients. Subjects and Methods: This prospective case-control study included 80 subjects, divided into two groups: sepsis patient group, and Control group, each including 40 subjects. Subjects were subjected to full history taking and clinical assessment, routine lab investigations, sepsis biomarker assay and culture & sensitivity (for patients only), and determination of serum expression of miRNA-223, miRNA-193* and miRNA-150 using real-time PCR. Results: Micro-RNA expression profiles showed that miR-223 and miR-150 were up-regulated in sepsis patients in general, while miR 193b* was down-regulated. Only miR-223 showed a statistically significant good diagnostic performance when assessed by ROC curve (AUC=0.730, 82.5% sensitivity, 66.67% specificity, CI=0.593 to 0.841, p value <0.001). Regarding prognostic performance of studied miRNAs, all of them showed a statistically significant good performance in predicting patient survival in ROC curves. Both miR-150 and miR-223 were significantly different between survivors and non-survivors (p <0.01). Conclusions: All studied miRNAs can be used to predict survival in adult sepsis patients, but only miRNA-223 has a diagnostic value.