Giant hydronephrosis is uncommon. and malignant hydronephrosis of unknown origin is even rarer. We report a case of a 43-year-old male patient with giant hydronephrosis without painless carnivorous hematuria. Preoperative imaging and urinary search for exfoliated cells revealed no evidence of renal pelvic cancer. https://yeswellneses.shop/product-category/vein-health/