The authors report their experience on a case of crossed ectopic kidney without fusion associated with stenosis of the pyeloureteral junction and secondary pyelocaliceal staghorn calculosis. After a brief summary of the various types of kidney ectopia and related principles of operation they describe their case report underlying the rarity of their case and the surgical approach. They consider the anterior transperitoneal approach as the most indicated for this type of malformation as it permits a better surgical view of the kidney and of the vascular structures.