Abstract Objectives: The aim of this study was to investigate, by means of cDNA macroarrays, the expression profile of genes coding the ECM proteins in endometrial cancer. Material and methods: Tissue specimens were collected during surgical procedures. 40 patients were operated due to endometrial cancer and 9 patients because of uterine myomas. RNA was isolated and reverse transcriptase reaction with radioisotope labeling of cDNA were performed. PCR reaction was performed with labeled cDNA. All steps of macroarray hybridization were done according to the protocol. Statistical analysis was done with different tests, including artificial neural network method. Results: The level of ECM protein genes expression in normal endometrial tissue was compared to the expression of these genes in endometrial cancer specimens. Statistical significances were found only for fibronectin and osteonectin genes and for both genes decreased expression was observed in cancer tissues (p=0.009, p=0.0003, respectively). Moreover, fibronectin and osteonectin genes expression decreased along with increase of clinical staging and histological grading of the endometrial cancer but no statistical significance for this trend was found. Conclusions: Decreased expression of fibronectin and osteonectin genes, when compared to normal endometrial tissue expression, in endometrial cancer may play an important role as a stimulus for disease development and, on the other hand, may be used as an additional marker for the progression of the disease.