Objective: The aim of the study was to evaluate the relationship of ovarian tumour markers osteopontin (sOPN) and splice variant 6 of sCD44 (sCD44-v6) between serum and local environment, represented by ascites or peritoneal fluid (PF) / peritoneal washing (PW), in patients with malignant and non-malignant conditions, respectively. Materials and Methods: The study included 33 women with advanced ovarian malignancy and 33 women with benign gynaecological conditions. Tumour markers concentrations were determined by flow cytometry. Results: Mean concentrations in ascites for both tumour markers were significantly higher than in PF or PW. Serum sOPN concentrations did not correlate with local fluid levels in either group and showed a tendency for retention in local fluid which was potentiated in malignant condition. Serum sCD44-v6 concentrations positively correlated with concentrations in ascites, PF, and PW. However, the magnitude of slope of the regression line was lower in malignant situation. Conclusion: Although concentrations of both potential biomarkers significantly increase in ascites produced by metastatic ovarian cancer, serum values are not a simple reflection of local environment changes.