GIANT hydronephrosis is a rare urological entity.It was first defined as the presence of more than 1 000 mL of fluid in the collecting sys tem.1 That disease is seen more often in males than in females (2.4:1) and more often On the left side than on the right side (1.8:1).2 It is usually secondary to ureteropelvic junction obstruction,stone,or congenital abnormality.Among the etiologies of giant hydroureter onephrosis,obstruction of ectopic ureteral orifice into prostatic urethra is a very rare one.