Although alteration in the haptoglobin phenotype has been reported in patients with bladder cancer, serum haptoglobin levels have not been evaluated. We hypothesized that serum haptoglobin can be used as a biomarker.The aim of this study was to evaluate the expression of haptoglobin in bladder cancer and to determine the relationship with clinicopathological features. A total of 68 serum specimens obtained before surgery were usedto investigate haptoglobin expression using the sandwich ELISA technique. Serum haptoglobin levels were higher in the patients with bladder cancer compared to healthy controls (p<0.0001). Additionally, the levels ofhaptoglobin protein increased with increasing tumor grades (p<0.001) and were significantly higher in patients with metastatic disease and the presence of lymphovascular involvement, lymph node metastases and increasingtumor burden (p<0.0001). This study suggests that elevated haptoglobin levels are associated with a higher stage, grade, and extent of distant metastasis and larger tumor size. Haptoglobin may therefore provide a useful diagnostic and treatment biomarker for patients with bladder cancer.