Background: The incidence of horseshoe kidneys is between 1 in 300 and
1 in 1600. Horseshoe kidneys may be either transplanted into two reci
pients after division of the kidney, or used for en bloc transplantati
on into one recipient. Methods: We report two cases of adult-to-child
and child-to-adult transplantation of horseshoe kidneys. Embryology an
d associated abnormalities are outlined, and previous case reports rev
iewed. Results: One transplant was successful and one transplant faile
d due to an unrecognized C peptide deficiency. Conclusions: Horseshoe
kidneys are acceptable as donor organs in renal transplantation.