OBJECTIVE: We reported recently the hypermethylation of LMX1A, a LIM-homeobox gene, as a prognostic biomarker in ovarian cancer; however, the function of LMX1A in ovarian cancer remains unknown. The present study aimed to evaluate the hypothesized tumour-suppressor functions of LMX1A in ovarian cancer. METHODS: We analysed the function of LMX1A by examining cell lines, animal models and human ovarian cancer tissues. Overexpression of LMX1A in relation to chemotherapy was also analysed. RESULTS: The expression of LMX1A inhibited cell proliferation, migration, invasion and colony formation in vitro, as well as tumourigenicity in a xenotransplantation mouse model. LMX1A also sensitized ovarian cancer cell lines to chemotherapeutics, and affected epithelial-mesenchymal transition (EMT). The restoration of LMX1A down-regulated stem cell markers and inhibited tumour spheroid formation in SKOV3 cells. Univariate analysis of immunohistochemical staining of tissue arrays (n=83) revealed that low LMX1A expression was significantly associated with advanced stages (p=0.001), poor differentiation (p<0.001), early recurrence (p=0.023) and poor overall survival (p=0.042) in ovarian cancer. CONCLUSIONS: The present study demonstrated, for the first time, that LMX1A is a bona fide tumour suppressor of ovarian cancer. The prognostic values of LMX1A may provide a biomarker for personalized treatments of ovarian cancer patients. The mechanisms of LMX1A in EMT and stem-like properties in ovarian cancer warrant further investigation.