Biological behavior of ovarian carcinomas might be the result of cellular diversity existing in tumor tissue, which consists of differentiated and undifferentiated cells showing stem cells biological properties and function. We examined correlation between p53 protein phosphorylated at serine 20 (p-p53(Ser20)) and CD133, SOX2, Notch1 expression, in order to reveal p-p53(Ser20) stemness function in ovarian cancer. p-p53(Ser20), CD133, Notch1, SOX2 expression was analyzed on 104 ovarian carcinomas using immunohistochemical staining. The positive correlation between p53 and p-p53(Ser20) (p=0.02), p53 and SOX2 (p=0.02), p-p53(Ser20) and Notch1 (p=0.03), p-p53(Ser20) and CD133 (p=0.01) expression was observed in ovarian carcinomas. The parallel expression of p-p53(Ser20)/CD133, p-p53(Ser20)/Notch1 reflecting co-expression of these proteins in single carcinoma cell, and p-p53(Ser20)/SOX2 expression was associated with advanced stage and p-p53(Ser20)/Notch1, p53/SOX2, p-p53(Ser20)/SOX2 parallel expression correlated with high tumor grade. The correlation between p-p53(Ser20) and CD133, Notch1, SOX2 expression and clinical parameters indicate, that malignancy and biological behavior of ovarian carcinomas depend on interaction between p-p53(Ser20) and carcinoma stem cells biomarkers expression.