Sonography was compared to pH-metry and/or oesophagomanometry to evaluate the accuracy of sonography in the early diagnosis of gastro-oesophageal reflux. Thirty children with a mean age of 72 days (21-252 days) were studied. The results showed that specificity of sonographic diagnosis was 87.5% and sensitivity was 100% (with P less than 0.001). Sonography also proved helpful in providing both functional and morphological data in addition to pH-metric results. This study therefore suggests that sonography is useful as the first approach in the diagnosis of vomiting babies as it is non-invasive and provides sufficient diagnostic accuracy.