The use of irrigating solutions is essential for distension of mucosal surfaces and visualization of the surgical field during resectoscopic resection of bladder tumors (TURBT). TURBT resection may be complicated with bladder perforation associated with intraperitoneal extravasation of irrigant fluid, which may rarely evolve in specific hydroelectrolyte imbalance characterized with hyponatremia, intravascular volume deficit, and renal impairment. We report four cases of TURBT syndrome during bladder surgery complicated by bladder perforation and discuss issues relevant to pathophysiology, diagnosis, and treatment of this rare condition.