Urine cytology is a test to look for abnormal cells in your urine. Urine cytology is used along with other tests and procedures to diagnose urinary tract cancers.Urine cytology is most often used to diagnose bladder cancer, though it may also detect cancers of the kidney, prostate, ureter and urethra.Your doctor may recommend a urine cytology test if blood has been detected in your urine (hematuria).Urine cytology may also be used in people who have already been diagnosed with bladder cancer and have undergone treatment. In these cases, a urine cytology test may help detect a bladder cancer recurrence.