We present a 7-month-old boy with a giant abdominoscrotal hydrocoele associated with right leg oedema. US revealed an abdominoscrotal fluid-filled mass with a normal testis in the scrotum. MRI allowed precise delineation of the mass while MRA sequences showed extrinsic compression of the right iliac vein and its patency. Hydrocoelectomy and laparotomy were performed and confirmed the diagnosis. US followed by MRI are often necessary to diagnose and delineate giant hydrocoeles. MRA is a non-invasive elegant tool for the detection of vascular complications.