We reviewed risk factors of failure to pneumatic reduction in intussusception: children younger than 12 months (p = 0.001), weight <12 kg (p = 0.013), median duration of symptom to presentation >24 hours (p=0.001), vomiting (p=0.001), dissipation of blood (p=0.001), fever (p=0.001), lethargy (p=0.001), abdominal distention (p=0.001), palpable mass (p=0.001), fluid trapped within intussusception (p=0.001), bowel wall thickening (p=0.027), decreased intestinal perfusion (p=0.004), location of the mass on the left side (p=0.001).