OBJECTIVE To assess the role of echography in the diagnosis of acute abdominal symptoms in children. METHODS Prospective, descriptive. METHODS During one year (1 June 1999-31 May 2000), abdominal ultrasonography was performed in all children with abdominal pain less than 2 weeks, who were referred to the emergency department of the Red Cross Hospital in The Hague (the Netherlands). An initial clinical diagnosis was made on the basis of the medical history, a physical examination and the results of laboratory tests. Subsequently, ultrasonography was performed by a radiologist who was unaware of the clinical diagnosis. A working hypothesis was reached on the basis of the clinical findings and the results of echography. The final diagnosis was made on the basis of either a histologic investigation after surgery or the condition at discharge. RESULTS The study included 112 patients. The mean age was 9 years and 54% were boys. Acute appendicitis was ascertained in 48 children. The sensitivity of the clinical findings was 88% and the specificity 70%. The sensitivity of the clinical findings together with ultrasonography was 88% and the specificity 91%. The positive predictive value of the clinical findings alone was 69% and of the clinical findings together with ultrasonography 88%. CONCLUSIONS Echography has added value in the diagnosis of acute abdominal pain in children; it increases the specificity of the physical examination. The number of negative laparotomies was decreased by the use of ultrasonography.