99mTc colloid scintigraphy is a sensitive technique for the detection of gastro-oesophageal reflux, compared to X-ray studies. A quantification index of reflux is used and can be of value when there is concern about the significance of a positive result. Continuous monitoring during one hour increases by 25% the detection of reflux in comparison with a 30 min test. In our series, no case of lung aspiration was recognized using this technique. The scintiscanning index cannot predict the existence of an associated oesophagitis.