This chapter provides an overview of pediatric surgery of umbilical hernia, congenital hydrocele and undescended testis. Umbilical hernia is the protrusion of the abdominal contents through a weakness in the umbilical cicatrix. It has an equal sex distribution with a relatively higher incidence (up to 75%) in premature infants. The incidence is higher in patients with congenital hypothyroidism and certain genetic predilections like Down syndrome, Trisomy18, Trisomy13, mucupolysaccharidosis and Beckwith-Wiedemann syndrome. Most umbilical hernias after the age of 2 years are not likely to resolve spontaneously and the patients may then be advised to undergo an elective repair. In case, an umbilical hernia gets incarcerated before the age of 2 years, an attempt may be made to reduce the same under sedation. Surgery for umbilical hernia in children involves dissection of the sac all around the ring, ligation of the sac at its base and closure of the ring (usually double-breasting). A hydrocele is a collection of fluid in the tunica vaginalis sac. Normally, the tunica vaginalis sac is a potential space, which has a very thin layer of fluid. Fluid accumulation in this potential space can result either from excessive production or due to poor absorption. In the newborns, there is also an element of immaturity of lymphatics draining the scrotal area and this contributes to excessive fluid collection. This immaturity of lymphatics is known to improve by about 6 months of age and most such hydroceles in newborns gradually reduce in size to disappear by 6 months of age. Testicular descent takes place under the influence of the sex-determining region of Y-chromosome (SRY) gene on the \'Y\' chromosome of the fetus. The testes develop within the abdomen from the indifferent gonad in the first trimester of pregnancy. By the third month, they lie adjacent to the internal inguinal ring. During the third trimester, they begin to descend through the inguinal canal to reach the scrotum, by birth. Descent of the testes is important for adequate germ cell development, since the scrotum maintains the testes at a temperature a few degrees lower than the body core temperature. The undescended testicle is surrounded by an osseomuscular compartment and is thus far more prone to traumatic injury as compared to the loose scrotal position.