A portable glucometer method was used to measure clearance of salivary glucose in 31 black and in 28 white 12-year-old school children. The aims of this study were to evaluate a readily available portable glucometer method and to investigate salivary glucose clearance as a marker of caries risk. Following the initial evaluation, we adapted the portable adapted glucometer method and found it reproducible and suitable for the measurement of salivary glucose clearance. Black children had almost double the salivary clearance rates of white children. No significant differences in salivary glucose clearance were seen between caries free (DMFT = 0) and caries active (DMFT > or = 3) children. Salivary glucose clearance is not suitable as a single caries risk predictor.