Thirty consecutive patient seen in a pediatric out patient and emergency department, in whom the diagnosis of intussusception was considered, had an ultrasound examination of the abdomen before the barium enema. The peak age was 5~12 month (range 4~34 month). Intussusception was detected by ultrasonography in all 25 cases proved by barium enema (sensitivity 100%). Normal findings on ultrasonography correlated with a negative barium enema results in 5 of 5 cases (negative predictive value=100%). No intussusception was missed by ultrasonography. To determine which patient would most benefit from ultrasonography, we divided patients into either a high risk group (100% intussusception) or a low risk group (37.5% intussusception) on the basis of clinical symptoms. We conclude that ultrasonography can be used as a rapid sensitive screening procedure in the diagnosis or exclusion of childhood intussusception. Probability of surgical reduction was associated with size of of total thickness and external rim thickness.