The diagnostic and therapeutic value of cystocentesis has been recognized for over 80 years. In feline patients with nonobtrusive lower urinary tract diseases (LUTD), normal patients, or patients with nonurinary disorders, diagnostic cystocentesis circumvents many of the potential problems associated with collection of urine specimens by normal micturition, manual compression of the urinary bladder, or catheterization. In patients with obstructive LUTDs, therapeutic cystocentesis temporarily halts the adverse effects of obstructive uropathy and may provide additional time to remove or bypass the obstructive lesion. In our experience, cystocentesis has been associated with few significant side effects; however, it may induce mild transient microscopic hematuria which may be indistinguishable from pathologic hematuria associated with many naturally occurring feline LUTDs.