The aim of the present study was to determine the reproducibility of measurement of resting metabolic rate (RMR) using a ventilated-hood indirect calorimeter in children using a short protocol suitable for the outpatient setting or home visit. The protocol consisted of an overnight (10–12 h) fast, 5–10 min supine rest, 5–10 min ‘settling in’ under the ventilated hood, and 12–16 min of measurement. Three measurements of RMR were made in eighteen healthy children (nine boys, nine girls, aged 6–11 years) on alternate days. Reproducibility of RMR was assessed using a reproducibility index and by calculating the CV for intra-individual measurements. The mean CV was 2·6 (sd 1·7)% and the reproducibility index was 95·0 %, indicating excellent reliability. The short protocol had higher reproducibility than more stringent protocols described in the literature. The new protocol has a number of practical advantages and should be adequate for most clinical or research purposes.