Background: Cell division cycle 20 (CDC20) is frequently overexpressed in malignant tumours and involved in the differentiation process of hematopoietic stem cells. However, the role of CDC20 in prostate cancer stem-like cells (CSCs) remains poorly understood. Methods: The expression of CDC20, CD44, beta-catenin were examined in prostate cancer specimens by immunohistochemistry assay, the role of CDC20 on the stem-like properties of prostate CSCs was accessed by real-time quantitive PCR, spheroid formation, in vitro and in vivo limiting dilution assay. Finding: CDC20 was associated with malignant progression of prostate cancer, the patients with both high expression CDC20 and CD44 or beta-catenin were associated with more aggressive clinicopathological features and poor prognosis. CDC20 was usually enriched in CD44(+) prostate CSCs. Knockdown of CDC20 could inhibit the expression of stemness-related genes, self-renewal ability, chemo-resistance, invasion capability and tumorigenicity of CD44(+) prostate CSCs. Mechanistically, CDC20 promoted degradation of Axin1, the core member of beta-catenin destruction complex, sequentially reduced the phosphorylation of beta-catenin, promoting the latter into the nucleus, thereby enhancing the self-renewal capacity of CD44(+) prostate CSCs. Interpretation: Our results indicated that CDC20 maintains the self-renewal ability of CD44(+) prostate CSCs by promoting nuclear translocation and trans-activation of beta-catenin. In addition, CDC20 combined with CD44 or beta-catenin can serve as an important indicator for prognosis of patients with prostate cancer. (C) 2019 The Authors. Published by Elsevier B.V.