Abstract The importance of tumor-stromal cells interactions in breast tumor progression and invasion has been recognized; therefore, modifications in the stromal fibroblasts can play a significant role in overall cancer development and progression. Accumulating evidence indicates that epigenetic phenomena such as microRNAs are extremely important and were already recognized as key regulators of gene expression, as well as expression of these small RNAs has been linked to human disease, including those related to estrogen-dependent disorders and in cancer homeostasis. So, deciphering molecular alterations in breast tumor microenvironment such as miRNAs differential expression could lead not solely to target for therapeutic intervention as well as to novel early diagnosis markers. Stromal fibroblasts were isolated from four invasive breast carcinoma samples (CAFs) and from five women with benign breast disorders (NAFs). RNA was extracted from low-passage cultures and transformed into cDNA and used for the Human Breast Cancer miScript® miRNA PCR Array expression analysis on StepOne Plus Real Time. This Array profiles the expression of 84 mirRNAs known or predicted to alter their expression during breast cancer initiation or progression. We could find 05 differentially expressed miRNAs in CAFs in comparison to NAFs; 04 down-regulated: mir107 (fold: -1,56, p = 0,04), miR-125b-1 (fold:-1,83, p = 0,03), miR-200b (fold: -2, p = 0,02), miR-93 (fold: -2,25, p = 0,02) and 01 up-regulated: miR-424 (fold: 5,73, p = 0,01). After bioinformatics analysis, these miRNAs were predicted to regulate genes involved in important cancer related pathways like, Cyclins and Cell Cycle Regulation; EGF Signaling Pathway; MAPKinase Signaling Pathway and Apoptotic Signaling in Response to DNA Damage. All together, our results showed that there are important differences regarding miRNAs expression profiling between CAFs and NAFs that could be determinant for breast cancer tumorigenesis. Citation Format: Patricia Bortman Rozenchan, Cristina V. de Carvalho, Tatiana Bonetti, Carina Melo, M Mitzi Brentani, Manoel JBC Girão. miRNA differential profiling between fibroblasts originated from breast cancer and normal adjacent tissue from benign disease. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1970.