The search for interacting long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs of protein-coding genes through the mechanism of competing endogenous RNAs in tumors of ovarian cancer patients was carried out. The levels of expression of 24 lncRNAs, 20 miRNAs, and 28 mRNAs of protein-coding genes involved in oncogenesis were determined by real-time PCR on a set of representative samples. Correlations between lncRNAs/miRNA and miRNA/mRNA levels in ovarian cancer samples were analyzed. We identified 8 pairs of lncRNAs/miRNA and 17 pairs of miRNA/mRNA, the expression levels of which have a negative correlation. Five triplets of potentially interacting lncRNAs/miRNA/mRNA have been identified, among which the most significant triplet is the OIP5 - AS1 / miR-203a-3p / ZEB1 . The data obtained determine new epigenetic profiles, as well as new potential biomarkers and targets for targeted therapy of ovarian cancer patients.