The horseshoe kidney is a congenital fusion anomaly of the kidneys with an incidence of 0.25% in the general population. We present an anatomical and histological study of a horseshoe kidney with abnormal vascular supply found during a routine dissection at a formalin-fixed male human body at the School of Medicine of the University of Caxias do Sul. This horseshoe kidney was joined at the lower poles by an isthmus of parenchymatous tissue. The vascular and excretory system is also discussed. We also present an embryologic review and the clinical and surgical importance of this anomaly.