Undescended testis is a condition in which one or both testicles fail to descend into the scrotum before birth. Normally, the testes develop in the abdomen during pregnancy and gradually move down into the scrotum. When this process does not occur completely, the testis may remain in the abdomen, groin, or higher scrotal position. Early identification and treatment are important because an untreated undescended testis can affect future fertility, increase the risk of testicular torsion, hernia, and slightly raise the risk of testicular cancer later in life. With timely evaluation by a pediatric surgeon, most children can be treated safely, restoring normal testicular growth and function.