Risk of thermal injury to the bowel when utilizing electrocautery at the bladder dome has been reported anecdotally. This is a case report of a 64-year-old man with urothelial carcinoma in situ of the bladder who underwent transurethral resection of bladder tumor at the posterior bladder wall near the dome without evidence of perforation. The postoperative course was complicated by delayed small bowel perforation likely secondary to transmission of thermal energy during fulguration of the resection bed. This injury highlights the need for particular prudence when resecting and fulgurating bladder tumors using monopolar electrocautery, specifically in the regions adjacent to bowel.