Some studies have shown an increased risk of urothelial carcinoma among renal transplant recipients. Associations of post-transplant urothelial carcinoma with immunosuppression and the consumption of Chinese herbal preparations and compound analgesics have been reported. We report 2 cases of de novo urothelial carcinoma after kidney transplantation. Case 1 was a 39-year-old male who underwent kidney transplantation 11 months before he was diagnosed with urothelial carcinoma of the right renal pelvis. Case 2 was a 32-year-old female who received kidney transplantation 33 months before bladder urothelial carcinoma was found. In our experience, symptomatic hematuria is a danger signal that a renal transplant recipient might have urothelial carcinoma.