The effect of 3 ml.kg-1 of apple juice given 2.6 +/- 0.4 hours preoperatively was investigated in 80 healthy children of ages five to ten years in this prospective, randomized, single blind study. The children who drank apple juice preoperatively had decreased gastric volume, thirst, and hunger (p less than 0.05). The gastric volume in the control group was 0.43 +/- 0.46 ml.kg-1 and in the patients who received apple juice the gastric volume was 0.24 +/- 0.31 ml.kg-1. The gastric pH was not significantly different, with the control group's gastric pH being 1.7 +/- 0.6 and the treated group's pH was 2.2 +/- 1.2. Further studies of the effects of different volumes and timing of preoperative clear fluids are indicated in paediatric patients.