Colorectal cancer (CRC) is multifactorial disease with complex etiology and high prevalence among population. In most cases it arises from initially benign adenomas that become malignant after series of gene mutations in colon epithelial cells. It is characterized by slow development and long presymptomatic phase which gives opportunities for early detection and treatment. Liquid biopsy is non-invasive method for determination of cancer molecular profile including CRC, while exosomal RNAs and miRNAs are promising biomarkers for diagnosis, prognosis, and evaluation of therapy response in CRC patients. The goal of this research was to optimize the method for assessment of RNA and miRNA isolated from exosomes of CRC patients found to be promising potential prognostic and therapeutic markers of this disease. RNA was isolated from exosomes from plasma of 18 patients diagnosed with CRC. Expression of C-MYC and reference B2M, PPIA and GAPDH genes was determined using qPCR and TaqMan assays, and expression of miR-19a-3p, miR-92a-3p, miR-125-3p, miR-193a-3p, miR-210-3p and three reference miRNAs: mir-103a-3p, mir 1228-3p and miR-520d-3p was determined using SYBR green technology. Concentration of RNA ranged from 2,44 ng/μl to 51,20 ng/μl with median of 11,48 ng/μl. C-MYC gene and three reference genes weren’t detected in any sample what can imply that these mRNAs are too big for packing in exosomes. On the other hand, only miR-103a-3p was detected of three potential reference genes, which is why UniSp6 was used as standard to normalise expression of target miRNAs. MiR-19a-3p and miR-92-a-3p were detected in most samples (18) while miR-125-3p was detected in lowest number of samples (3). We can conclude that despite low concentrations, our samples have sufficient quality for determination of the expression of most of the targeted miRNAs in this research, but the same cannot be said for mRNAs.