The clinical and radiological features of one case of renal hydatid di
sease communicating with collecting system are described. Introduction
of hydatid elements into the renal pelvis due to rupture was accompan
ied by six episodes of renal colic. Although the sonographic features
of renal hydatid disease have been described extensively, direct demon
stration by ultrasonography of hydatid cyst ruptured into the renal pe
lvis has not, to our knowledge been previously reported. The diagnosis
has also been confirmed at surgery.