• Pediatric inguinal hernias are typically indirect inguinal hernias occurring from a patent processus vaginalis. Indirect inguinal hernias occur lateral to the epigastric vessels and account for 90% of all inguinal hernias in children.  – Direct inguinal hernias occur medially to the epigastric vessels and rarely affect children, more commonly found in adolescents.  – Femoral hernias occur inferior to the inguinal ligament; they are very rare and more commonly found in females. • Incidence of inguinal hernia in full-term newborns is 0.8–5.0%. Incidence is higher in premature infants, 13% in those born <32 weeks’ gestation. • Incidence of inguinal hernias is five to ten times higher in males. • Increased abdominal pressure predisposes development of inguinal hernias: ascites, peritoneal dialysis, ventriculoperitoneal shunts, intubation, cystic fibrosis, and chronic lung diseases. • Hernias are twice as common on the right; the right processus vaginalis closes after the left during embryologic development. • Diagnosis of an inguinal hernia is clinical and rests on history and physical examination. Presentation is an asymptomatic child with intermittent, unilateral inguinal bulge. Activities that increase intra-abdominal pressure (crying, straining, coughing) will elicit the hernia.  – Radiologic assessment is not usually necessary. Ultrasound can be used to identify a widened internal inguinal ring (4–5 mm) or a patent processus vaginalis, but it is highly operator dependent. • Incidence of incarceration is high, 5–18% in children and up to 30% in premature infants; children with incarceration present with pain, abdominal distention, emesis, and erythema. • Differential: hydrocele, testicular torsion, epididymitis, and tumor.