The aim of this study was to detect the expression of microRNA-200c and epithelial-mesenchymal transition (EMT) in the mesothelial cells of the peritoneal dialysate effluent fluid of peritoneal dialysis (PD) patients, and to investigate the association between microRNA-200c and peritoneal mesothelial cell EMT. Twelve patients who had recently started continuous ambulatory peritoneal dialysis (PD start group) and 16 patients who had been undergoing peritoneal dialysis for >6 months (PD >6 months group) were randomly chosen for the isolation, culture and identification of effluent cells. qPCR and western blot analysis were used to detect the expression levels of microRNA-200c and the levels of four cellular marker proteins, E-cadherin, vimentin, fibronectin (FN) and COL-1, in effluent cells. The results showed that the effluent cells in peritoneal dialysis were peritoneal mesothelial cells. The level of E-cadherin protein expression was significantly lower in the PD >6 months group than in the PD start group, while vimentin, FN and COL-1 protein expression levels were significantly increased in the PD >6 months group. microRNA-200c in the PD >6 months group was significantly downregulated. The E-cadherin protein expression level was significantly decreased and vimentin, FN and COL-1 protein expression levels were significantly increased in the PD >6 months group. The level of microRNA-200c was significantly reduced in the PD > 6 months group, suggesting that microRNA-200c may be associated with EMT.