An ectopic kidney is a congenital anomaly in which a well-developed kidney fails to reach its normal position in the retroperitoneal renal fossa. Most ectopic kidneys are located in the pelvis, a few in the contralateral side, and very rarely in the thoracic cavity, and are often associated with malrotation, as well as ureteral and vascular anomalies, but their ureteral openings in the bladder are still normal. It is primarily a developmental disorder caused by the kidney during embryonic ascent and rotation of the embryo during the embryonic period. The germ is located in the pelvic cavity during fetal life, and as the fetus grows, the kidney gradually rises to its normal position, and if the ascent is impaired or incorrect an ectopic kidney can occur. Clinically, there can be colic in the ureter, abdominal mass, urinary tract infection, hydronephrosis, and stone manifestations. Most ectopic kidneys in the thorax are asymptomatic, and the opposite kidney of the ectopic kidney is mostly normal, and some of them may be accompanied by malformations of the genital organs. Asymptomatic patients do not need to be treated in this case, but care should be taken to prevent complications. In case of pyelonephrosis, stones, or persistent infection, surgical treatment is needed, and patients with infection should be treated with sensitive antibacterial drugs.