Background: Pancreatic ductal adenocarcinoma (PDAC) is the most common type of PCa with 2-9% 5-year survival rate. PDAC is the most lethal malignancy worldwide and hence the molecular mechanisms, which are linked to the aggressive features, should be further examined to develop better diagnostic, prognostic and therapeutic agents. microRNAs (miRs) are small non-coding RNAs (18–24 nucleotides), that can control cell growth, proliferation, apoptosis, differentiation, metastasis and angiogenesis. Furthermore, several studies have suggested that miRs could be utilized for the discrimination between PDAC and non-malignant lesions and thus the evaluation of them as novel diagnostic biomarkers is crucial for PDAC. Aim of this study is to examine miRs and their role in PDAC progression and metastasis. Methodology: miR expression levels of paired normal and malignant pancreatic tissue samples from ten PDAC patients were analyzed by using their RNA-sequencing data. Then, their cellular and molecular functions as well as the associated molecular signaling pathways with the target genes were identified. The most significant miRs were selected based on their fold changes (FC) and p-value (p<0.05). Data analysis was performed by using SPSS software and specifically paired t-tests between normal and malignant patient tissue samples. Moreover, expression levels of the most significantly altered miRs were further analysed by using Panc-1, CAPAN-2, MiaPaca-2 and Panc10.05 PDAC cell lines. Results: 31 upregulated and 13 downregulated miRs were reported, approximately 3000 target genes were detected to be modulated by abnormally expressed miRs, while the bioinformatic analysis disseminated that the dysregulated miRNAs were correlated to numerous signaling pathways such as EGF-Jak-STAT, KRAS/NRAS and PI3K. The PDAC cell line-based analysis confirmed the aberrant miR expression. Conclusions: Taking the data together, we suggest that specific miR signature profiles could prove useful for PDAC in order to determine patient diagnosis and prognosis. miRs modulate expression of other miRs and/or genes, which are interrelated with metastasis in human neoplasms. In addition, both form mutual feedback circuits, thereby increasing the connectivity and complexity of the regulatory network. Targeting this network will facilitate not only the development and advancement of miR-based clinical applications, but also will illuminate the gap between genotypic and phenotypic features of PDAC. Conclusively, the findings of this research could be the cornerstone of a pioneer precision medicine era of research.