Although Dickkopf-1 (DKK1) has been demonstrated to be associated with tumorigenesis in various types of human tumors, a correlation between DKK1 and urothelial carcinoma (UC) has not been reported. In the present study, the correlation between DKK1 expression and UC progression was investigated. Seventy-five UC patients were enrolled. The expression of DKK1 in serum and UC tissue was detected by ELISA, real-time PCR and Western blotting. Prognostic significance was assessed by using Kaplan-Meier survival estimates and log-rank tests. The results showed that serum levels of DKK1 were significantly higher in the UC patients with muscle-invasive (p=0.0001) and high-grade tumors (p=0.00001) as compared to the controls. A high-serum DKK1 was also associated with poor disease-free survival in the UC patients (hazard ratio=2.44; 95% CI 1.10-5.40; p=0.028). Furthermore, DKK1 was also overexpressed in 93% (41/44) of the UC tissues. Therefore, the findings indicate that the expression of DKK1 is associated with UC progression.