The present study aims at establishing the exact role and limitation of ultrasound in pediatric acute abdomen.Fifty children less than 14 years of age presenting with acute abdomen were evaluated by US and other imaging modalities. The mean age of presentation was 3 1/2 years. Maximum number of cases were seen in less than two years of age. There were 17 cases of intussusception with US sensitivity and specificity of 88.2% and 100% respectively and positive and negative predictive values of 100% and 94.5% respectively. There were 13 cases of appendicitis. US was diagnostic in 11 with sensitivity and specificity of 91.6% and 97%; the positive and negative predictive values were 91.6% and 97% respectively.There were two cases each of congenital bands, adhesive intestinal obstruction, malrotation of bowel with volvulus, incarcerated inguinal hernia, hypertrophic pyloric stenosis, duplication cyst and pseudopancreatic cyst, one case each of trichobezoar, Meckel's diverticulum, ureteric calculus and worms as a cause of intestinal obstruction. The sensitivity of US for diagnosing specific cause of acute abdomen was found to be 77.5%. The main limitation of US was in the diagnosis of acute intestinal obstruction such as congenital bands and adhesions.US should now be considered as imaging modality of choice in pediatric acute abdomen. However, at times, plain radiography, conventional contrast studies and CT may be vital to reach the true diagnosis.