Metrizamide (amipaque) has not been used previously as a diagnostic contrast agent in the gastrointestinal tract. Metrizamide is a water-soluble isotonic contrast material having many advantages over barium and existing hypertonic water-soluble agents. There are many clinical situations in children in which metrizamide should be the contrast agent of choice for investigating the gastrointestinal tract. Four neonates are presented in whom barium or gastrografin were absolutely contraindicated. In each case metrizamide gave excellent visualization of the gastrointestinal tract. It could be followed through be bowel giving excellent visualisation even up to 120 h after ingestion. No harmful effects were noted in the four cases studied.