This bladder biopsy is from a female who received radiation therapy for cervical cancer. Following the completion of therapy, she developed urinary urgency, frequency, burning micturition, and gross hematuria. Cystoscopy showed a diffusely erythematous urothelium consistent with acute radiation cystitis. The image shows ulceration of urothelial mucosa with fibrin deposition and acute and chronic inflammation in the lamina propria. The toxicity of radiation on the bladder is dependent upon both the duration of exposure and the dose. The acute symptoms appears within weeks of discontinuation of radiation. Late effects may be seen decades later.