OBJECTIVE: The aim of this study was to use Bolton calculations to compare and detect tooth size discrepancies which may exist between Caucasian and Chinese subjects. MATERIALS & METHODS: Fifty Caucasians and fifty Chinese subjects' study casts (25 male and 25 female) were selected who had a complete permanent dentition up to the first molars, without interproximal restorations or caries, and had no previous orthodontic treatment. Casts were measured with a Digital Caliper (accurate to 0.001"). The measurements were used to do the Bolton calculations for the over-all ratio (Overall 12) and for the anterior ratio (Anterior 6). Linear regression models with main effects for race and gender as well as an interaction effect between the groups, were used. RESULTS: No significant gender difference (p > 0.05) was found for the Overall 12 and the Anterior 6. A highly significant difference (p = 0.007) was found amongst the two ethnic groups for the Overall 12, but not for the Anterior 6 (p >0.05). For the Anterior 6 there was a significant difference (p = 0.04) in the group variances, with the Caucasian group showing more variance. CONCLUSIONS: Based on the findings in this study, for improved accuracy, it is advisable to generate Chinese-specific Bolton tables.